The "Fred thread": the Argead Macedonian Army

[PMBardunias]

The antilabe would not have to have been moved to the shield's edge, only lengthened into a loop through which the forearm could pass. The porpax, though, would have jutted out and prevented the bearer from tucking into the curvature of the shield, and so it would then need to be removed.

Ah, I see now. You would turn the antilabe into a porpax essentially. It could work, in extremis, but that is a lot of shield hanging off to your left. There are problems with how the strap would hang to bear the shield's weight evenly. I think you really need to experiment with this, or enlist someone to, if you are going to advocate it in a more formal setting.

As to the need to remove the old porpax, it is beyond the elbow in the position you suggest, so I don't think it would be a problem. See below:

[Paullus Scipio]

Paralus wrote:

MeinPanzer wrote:Secondly, the Achaeans did adopt the Argive aspis, and not the Macedonian shield (Pausanias, 8.50.1). However, this does not indicate that they re-armed their hoplites with such shields. It simply means that the phalangites used Argive aspides. Contra Paul, it would not have been physically impossible to carry the Argive shield while bearing the sarissa. We know that when Cleomenes III equipped his men as phalangites, he issued shields to them and taught them "to wield the sarissa with both hands and to bear the shield with strap (ochane), not with porpax" (Plutarch, Life of Cleomenes, 9.2). Once it is accepted that the phalangite did not have to employ a porpax to carry his shield, the offset rim and size of the hoplite shield are no longer impediments to wielding the sarissa.

Indeed. Those, though, sticking to the old view, would still argue the point. In his impecunious state, one hardly imagines Kleomenes commissioning the construction of purpose-designed shields as well as sarisae. Baldrics added to existing shields though... now there's a notion - particularly for those helots who'd bought their right to die at Sellasia.

And when he saw that the rest of the Macedonian troops also were drawing their targets from their shoulders round in front of them, and with long spears set at one level...


Plutarch (Amel.Paull. 19.2) describing the Macedonians at Pydna. Clealry they are pulling their shields from "their shoulders" and around in front of them. Thus they are not on the arm but slung from the neck by a strap.

I am surprised to see it being suggested that shields simply ‘hung’ from their neckstrap/telamones. This suggestion was largely discredited more than 35 years ago by Charles S. Grant among others, and Connolly and other re-enactors since. An old ‘canard’ that is as lame now as it was then ! To begin with, any shield unsupported by hand/arm will be driven in by the first serious blow it receives. Secondly, even a smallish 60- 70 cm shield is a severe encumbrance dangling thus – and anyone who has tried it can tell you that it is impractical to fight in this way. Any shield must be moved to parry – see any practical arms manual from any era. A soldier in combat unable to move his shield is a dead soldier – effectively shieldless.
Furthermore, as the Aemilius Paullus frieze illustration posted by Paul B. shows,(beating me to it!) in fact a porpax was used with the ‘Macedonian’ shield.
That this shield was not an ‘Argive’ aspis is shown by three things:
1. It is clearly rimless
2. Whatever time the infantry use of the ‘Argive’aspis ended, it was almost certainly long before 168 BC
3. Nowhere in the accounts of Pydna are there any references to Macedonian infantry who could be armed with an ‘argive’ aspis.

As for the Plutarch passage referring to the same occasion, the manuals make it clear that on the approach march, the sarissa was shouldered, as one would expect, and needed two hands to steady it .The shield, with porpax, thus hung beside the left arm/shoulder, perpendicular to the line of march. On the command being given, the sarissa was lowered and held horizontally at the right side. This action also brought the shield around from beside the shoulder to its proper ‘ready’ position.( see attached photo of Mathew Connolly demonstrating same, which I have posted before. See also P. Connolly JRMES 11 2000 for photos of group phalanx drill.)
The reference to Cleomenes troops is a literary flourish to emphasise the different method of shield use, and should be read as “bear the shield with strap, (partly) not with porpax (alone).
As Connolly points out ( e.g. P.75 Greece and Rome at War) a neck’strap was needed because the ‘Macedonian’ shield lacked the rim to allow it to be rested on the shoulder when not in use, and to help support the sarissa.

I believe the adoption of the thureos, which happened very likely first in Aetolia (but at what time before the 250s is unknown), was due to ease of construction and the overall flexibility of the arm. However, I don't think that the defeat of the Galatians by the Aetolians inspired them to adopt it - if anything, the weakness of the Galatians to missile fire was an indictment of the shield, which failed to provide ample protection (10.22.6).
I have already alluded to the fact that ‘enemy’ weapons can be adopted for a number of reasons, and I don’t think you would deny that ‘thureophoroi’ using Gallic style shields appeared in the aftermath of the invasion. The adoption, for whatever reason, was a direct consequence of the defeat of the Gauls by the Aetolians.


Paullus wrote:

The Boeotians seem to have been the first, shortly after 279 BC.(judging by several inscriptions, and tomb reliefs). However, by 245 BC, no more Gallic invasions having materialised, they switched to 'Macedonian' armament, having become an ally of Macedon.

If the Boeotians made the switch "shortly after 279 BC," then please produce an inscription or tomb relief which attests to the use of the thureos dating to before 250 BC.

The tomb of Eubolos, dated 275-250 BC ( see e.g. the Cambridge History of Warfare) – but I’m sure you expected me to say that! For further details see Feyel (Polybe et l'histoire de la Beotie) which discusses Boiotian inscriptions that describe young citizens being recruited into the thureophoroi - dating from about the 270s to 240s

Ruben/Meipanzer wrote:

There are two different types of cavalry shield: thureos-like and aspides. What evidence do you have that the large round cavalry shields employed in the Hellenistic period were single grip? I don't think I know of any evidence other than for such shields having porpakes and antilabai.

I think you misunderstand, of have maybe misread my post – I refer to both the the single-rib/single hand grip Italo-Gallic type, and the Greek type with porpax and antilabe. I was not suggesting ‘aspis’ types were single grip.

These aren't trophies, these are either votive offerings or, more likely, dedications made to the state with the explicit purpose of arming citizens. Usually these citizens were ephebes, but they could also be poor individuals or even mercenaries. These were kept all together in temple treasuries.

The arms supplied to war orphans and ephebes had to be stored somewhere, and just as the "emergency fund" of the state was to be found in the Acropolis (Thucydides 2.13.4), so too were arms. We, for instance, hear of 318 cases of arrows stored in the Hecatompedon and Opisthodomos IGII2, 1424a, l. 121-2) which certainly seem to be stored arms and are not listed as dedications.

You are quite right – for some reason I had it in mind that you meant dedicated captured trophies, overlooking the fact that Temples could be and were used as arsenals – indeed storehouses generally for ordinary goods, as well as those dedicated/belonging to the Gods.

I think it is clear that rim sizes could vary, and so only shields with smaller rims could have been used or, as you suggest, rims were cut down. But even so, I would suggest that a loose loop passing around the left wrist rather than an antilabe was in use. Such a loop was not necessary to support the shield, though, as that was the purpose of the telamon, and I disagree that it could not be used to effectively wield the shield. With such a large shield, as long as the phalangite could keep it in front of the exposed portion of his body, it was serving its purpose. And yes, keep in mind that I am only suggesting that this was a stop-gap measure - it may have been somewhat impractical, but if the rear ranks of a phalanx rarely engaged in close combat and yet needed to carry shields, this would have been a pragmatic compromise.

I don’t believe there is any convincing evidence for such a premise – cutting down the rim would compromise the structure and rigidity of the shield, and render it useless, I suspect that experimentally, small rims might have been added to ‘Macedonian’ shields is possible – the rim deflects a weapon sliding over the domed surface, so that it doesn’t come straight over the edge of the shield, a disadvantage of the rimless shield compared to the ‘Argive’ type.

Paralus wrote:
Agreed. The quote was simply a reaction to those (as Markle originally) dismissing shields such as those on the wall of the tomb of L&K as phalangite shields - insisting they are hoplite - as they do not match an uneccessarilly restrictive read of that passage of Ascepiodotus. It might appear, given the very close similarity, that these are little different to those on the Paullus monument.

It should be pointed out that it is more likely the shields in the Lyson and Kallikles tomb are quite possibly cavalry shields. The high-waisted armour depicted certainly is a cavalry cuirass c.f. Alexander mosaic, the Roman bronze of Alexander in the BM, and the Pelinna relief from Thessaly ( the latter two illustrated on pp5 and 8 of Sekunda’s “The Army of Alexander the Great”). I referred to the potential for confusion following the introduction of cavalry shields earlier e.g. the larger ‘Macedonian’ shields are now believed to be cavalry shields.( sorry, can’t find the ref at the moment)

[Astiryu1]

I'm sold on that representation. The wrist strap makes sense to me and allows for control of shield while using Sarissa or Knife/Shortsword.

[Paralus]

It should be pointed out that it is more likely the shields in the Lyson and Kallikles tomb are quite possibly cavalry shields.

Except for the similar shield in Pergamon and the exceedingly similar shields carried by infantry on the Paullus monument (and armour in as much as can be made out).

[PMBardunias]

Furthermore, as the Aemilius Paullus frieze illustration posted by Paul B. shows,(beating me to it!) in fact a porpax was used with the ‘Macedonian’ shield.
That this shield was not an ‘Argive’ aspis is shown by three things:
1. It is clearly rimless
2. Whatever time the infantry use of the ‘Argive’aspis ended, it was almost certainly long before 168 BC
3. Nowhere in the accounts of Pydna are there any references to Macedonian infantry who could be armed with an ‘argive’ aspis.

That shield, held as shown, could not be used as Connolly suggests. It is being held exactly as aspides, Argive or otherwise, have been held for centuries, with the hand well inside the curvature of the shield, not near the rim, and not so that the hand passes through the antilabe as Connelly did. There are many images of aspides in the classical period that show shields with greatly reduced rims.

But for porpaxes on peltae, see below from Ephesus:

[Paullus Scipio]

...that is because, simply put, the shield is being used in what may be termed "post sarissa" mode. This particular soldier is fighting with sword etc. The photos you attached quite clearly shows that 'Macedonian' shields had porpaxes....

Paralus wrote:

Except for the similar shield in Pergamon and the exceedingly similar shields carried by infantry on the Paullus monument (and armour in as much as can be made out).

The Pergamum shield matches the description in the manuals, as Connolly has demonstrated, and there is a clear distinction between 'foot' armour and the 'high waisted' cavalry cuirass. Compare distinctions between the flared cavalry 'muscled cuirass' and the 'foot version'. These are necessitated by the fact that the cavalryman has his hips splayed when mounted.....

[PMBardunias]

...that is because, simply put, the shield is being used in what may be termed "post sarissa" mode. This particular soldier is fighting with sword etc. The photos you attached quite clearly shows that 'Macedonian' shields had porpaxes....

I don't think anyone is saying that macedonian peltae didn't have porpaxes, I surely would not. I think Ruben is suggesting that an old fashioned aspis can be made to service as a shield for sarissaphoroi if you turn the antilabe into a 'porpax' and pass some half of the forearm through it in order to have the hand clear the rim. This is something that can be done, but if it would have been done by men who faced battle with such an unweildy thing is another matter entirely. I would prefer to simply saw the whole shoulder and rim section off my aspis, then fold over the bronze. This would no longer have the integrity of an aspis or even a properly made pelta, but would be better than the many flat plank shields used successfully by a wide variely of cultures. A poor quality shield you can move in the way of an oncoming weapon is better than a high quality wooden cape.

As to "modes" of use for the shield above, for this shield to have another mode, you would have to abandon the porpax, because clearly this man's arm cannot extend to the shield rim with his arm in the porpax shown. I agree with you that this is unlikely. More likely this is simply not a shield for sarissaphoroi- note there is no strap either. It may be of the same style as a Macedonian peltae, simply set up differently internaly.

[MeinPanzer]

I am surprised to see it being suggested that shields simply ‘hung’ from their neckstrap/telamones. This suggestion was largely discredited more than 35 years ago by Charles S. Grant among others, and Connolly and other re-enactors since. An old ‘canard’ that is as lame now as it was then ! To begin with, any shield unsupported by hand/arm will be driven in by the first serious blow it receives. Secondly, even a smallish 60- 70 cm shield is a severe encumbrance dangling thus – and anyone who has tried it can tell you that it is impractical to fight in this way. Any shield must be moved to parry – see any practical arms manual from any era. A soldier in combat unable to move his shield is a dead soldier – effectively shieldless.

All that these reenactors have shown with their limited tests is that some types of shield - Asclepiodotus' Macedonian shield - could be effectively employed with porpax. Once again, the purpose would not have been to deflect serious blows, nor to parry - they were probably just intended to be used as defense against missile weapons for those not in the front ranks. We hear about how phalangites were unsuited to fighting in close combat, and so it was perhaps thought to be worth it to arm a number of men with shields which conferred some defensive benefit, if not when it comes to close combat, in order to fill out the ranks.

The tomb of Eubolos, dated 275-250 BC ( see e.g. the Cambridge History of Warfare) – but I’m sure you expected me to say that! For further details see Feyel (Polybe et l'histoire de la Beotie) which discusses Boiotian inscriptions that describe young citizens being recruited into the thureophoroi - dating from about the 270s to 240s

The stele of Eubolos is dated to between 275 and 250 because it features thureoi and it is known that the first years the thureos could have been in use was the mid-270s, while it was no longer in use after 245 - so this does not provide any evidence for the date when the thureos came into use per se. Instead, we must rely on the two military catalogues which mention thureaphoroi, IG VII, 2716 and SEG 3, 351. On the latter the preamble listing the archons in office has been lost, and so it cannot be dated with precision beyond "pre-245;" the former, however, preserves the name of the federal archon Dorkylos, which means that it can be dated between 250 and 245. Therefore, the terminus ante quem for the adoption of the thureos in Boeotia is 250: almost exactly the same as for the Achaean and Aetolian leagues.

I think you misunderstand, of have maybe misread my post – I refer to both the the single-rib/single hand grip Italo-Gallic type, and the Greek type with porpax and antilabe. I was not suggesting ‘aspis’ types were single grip.

If I understood you correctly, and you were referring to the round cavalry shield furnished with a spina like the thureos, then I was challenging the fact that they are single grip, as you assert, and not equipped with a porpax. What evidence do you use to support this?

I don’t believe there is any convincing evidence for such a premise – cutting down the rim would compromise the structure and rigidity of the shield, and render it useless, I suspect that experimentally, small rims might have been added to ‘Macedonian’ shields is possible – the rim deflects a weapon sliding over the domed surface, so that it doesn’t come straight over the edge of the shield, a disadvantage of the rimless shield compared to the ‘Argive’ type.

So, in your view, how would the phalangite on the Pergamon battle plate with the domed shield with small rim be able to wield the sarissa with a porpax?

It should be pointed out that it is more likely the shields in the Lyson and Kallikles tomb are quite possibly cavalry shields. The high-waisted armour depicted certainly is a cavalry cuirass c.f. Alexander mosaic, the Roman bronze of Alexander in the BM, and the Pelinna relief from Thessaly ( the latter two illustrated on pp5 and 8 of Sekunda’s “The Army of Alexander the Great”). I referred to the potential for confusion following the introduction of cavalry shields earlier e.g. the larger ‘Macedonian’ shields are now believed to be cavalry shields.( sorry, can’t find the ref at the moment)

Certainly you do not think that the shield decorated "in the Macedonian manner" is a cavalry shield? In our fairly plentiful evidence from all over the Hellenistic world, we never see such shields in use among cavalry, only ever infantry. The single exception is a cavalrymen on a belt plaque from Basse Selce in Albania, but he is clearly an Illyrian cavalryman, as he wears an Illyrian helmet.

The panoplies don't necessarily relate to the single arms shown in the paintings, but simply seem to be generic trophies, since if they did each individual would possess two helmets.

Furthermore, as the Aemilius Paullus frieze illustration posted by Paul B. shows,(beating me to it!) in fact a porpax was used with the ‘Macedonian’ shield.
That this shield was not an ‘Argive’ aspis is shown by three things:
1. It is clearly rimless
2. Whatever time the infantry use of the ‘Argive’aspis ended, it was almost certainly long before 168 BC
3. Nowhere in the accounts of Pydna are there any references to Macedonian infantry who could be armed with an ‘argive’ aspis.

Except for the similar shield in Pergamon and the exceedingly similar shields carried by infantry on the Paullus monument (and armour in as much as can be made out).

That shield, held as shown, could not be used as Connolly suggests. It is being held exactly as aspides, Argive or otherwise, have been held for centuries, with the hand well inside the curvature of the shield, not near the rim, and not so that the hand passes through the antilabe as Connelly did. There are many images of aspides in the classical period that show shields with greatly reduced rims.

This shows that one kind of shield carried by a Macedonian infantryman was equipped with a porpax - which, again, I don't object to. But, again, Paul, how would a phalangite be able to carry such a shield and employ its porpax while also wielding a sarissa two-handed? Could such soldiers perhaps have not used the porpax, only slipping their left arm into it after they had dropped their sarissa and were preparing hurriedly to engage in close combat?

But for porpaxes on peltae, see below from Ephesus:

Unfortunately worth little, considering its late date (1st c. BC) and the tendency of artists at that time to produce fantastical weapons reliefs (see, for instance, the numerous Amazonian peltae depicted elsewhere on the monument).

[PMBardunias]

But, again, Paul, how would a phalangite be able to carry such a shield and employ its porpax while also wielding a sarissa two-handed? Could such soldiers perhaps have not used the porpax, only slipping their left arm into it after they had dropped their sarissa and were preparing hurriedly to engage in close combat?

The answer to the first question is that they would have to move the porpax off center towards the antilabe in order to allow the wrist to pas through it and extend beyond the rim of the shield. Off center porpaxes are not uncommon even in old-style aspides and such are shown on the reliefs at Ephesus for whatever they are worth. Given the state of preservation of dedicated arms that could be seen by contemporaries, I think they are more accurate than you give credit.

I see no reason to simply attack your notion of using just the wrist strap, bouncing off such ideas seems to me to be what RAT is for, but lets see how it would function. There is a problem with making the antilabe a porpax and using the strap to help support the sarissa's weight. See my diagram below. Because the strap is flexible, it cannot support asymetric loads without changing shape. To a sarissaphoroi this means a sawing across his neck as the side of the shield with the wrist falls, as in the central figure. The only way around this is to use a porpax to shift the force towards the center of the shield or move the attachment points of the strap left to shift the suspension system. This relies on the left hand portion of the shield counterbalancing the force on the right and pivoting on the left strap attachment. The problem is that the man's body limits how acute this angle can get, thus how much you can use to couterblance the sarissa's weight.

Of course this assumes that the strap was used in any way to support the weight of the sarissa. Later pikemen got along just fine without one. The problem here is that if its not helping you hold up the sarissa, its surely hindering you moving freely, so there must be a reason that they still drew their shields in front of them before battle other than as a big hanging pectorale.

[MeinPanzer]

The answer to the first question is that they would have to move the porpax off center towards the antilabe in order to allow the wrist to pas through it and extend beyond the rim of the shield. Off center porpaxes are not uncommon even in old-style aspides and such are shown on the reliefs at Ephesus for whatever they are worth. Given the state of preservation of dedicated arms that could be seen by contemporaries, I think they are more accurate than you give credit.

But the shield on the Pydna monument has a central porpax, perhaps even off-centre, but away from the antilabe side of the shield. Are you suggesting then that the soldier would adjust his porpax mid-battle? Or is the soldier on the Pydna monument a non-phalangite with a different kind of shield? And for larger shields, I would imagine that porpakes might have to be moved a fair distance off-centre. Have tests been done on how this affects the abilities of the bearer to wield it effectively in close combat?

I see no reason to simply attack your notion of using just the wrist strap, bouncing off such ideas seems to me to be what RAT is for, but lets see how it would function. There is a problem with making the antilabe a porpax and using the strap to help support the sarissa's weight. See my diagram below. Because the strap is flexible, it cannot support asymetric loads without changing shape. To a sarissaphoroi this means a sawing across his neck as the side of the shield with the wrist falls, as in the central figure. The only way around this is to use a porpax to shift the force towards the center of the shield or move the attachment points of the strap left to shift the suspension system. This relies on the left hand portion of the shield counterbalancing the force on the right and pivoting on the left strap attachment. The problem is that the man's body limits how acute this angle can get, thus how much you can use to couterblance the sarissa's weight.

Of course this assumes that the strap was used in any way to support the weight of the sarissa. Later pikemen got along just fine without one. The problem here is that if its not helping you hold up the sarissa, its surely hindering you moving freely, so there must be a reason that they still drew their shields in front of them before battle other than as a big hanging pectorale.

I don't envision the telamon being used to support the sarissa's weight - as you state, pikemen since have functioned just fine without such support. And Plutarch's (or rather Phylarchus') words are quite explicit: Cleomenes taught his phalangites to bear their aspides with ochane instead of porpax. The strap replaced the porpax as the primary means of supporting the shield's weight. The telamon therefore supported the shield's weight, the loop placed where the antilabe was was used to maneuver it, and the arms bore the weight of the sarissa. And why must there be a reason that they used their shields other than as a big hanging pectoral? For the majority of the men behind the front ranks, that's probably all their shields ever did, anyway.

[Old Husker]

I've been out of action for a few days and just came back on line to find a heck of a lot of discussion on this thread to catch up on. I don't want to break the flow, but , as requsted by Paul, here are literature references for the 4th century B.C. Macedonian vs Greek phalanx battles:

Macedonian victories = Pherae I 357/356 (Diod. 16.14.1-2), Pherae II 354 (Diod. 16.35.1-2), Crocus Plain 353 (Diod. 16.35.3-6), Olynthus III 348 (Diod. 16.53.2), Olynthus IV 348 (16.53.2), Chaeronea 338 (Diod. 16.85.5-86; Polyaenus 4.2), Megalopolis 331 (Diod. 17.62.6-63; Curtius 6.1.1-16), Upper Satrapies (Diod. 18.7), and Crannon 322 (Diod. 18.16.4-17.5). Greek victories = Pherae III 354 (Diod. 16.35.3-4), Crescent Hills 354 (Diod. 16.35.4-6; Polyaenus 36.3), Peloponnese 331 (Aeschines: Ctesiphon 165), Thermopylae II 323 (Diod. 18.12.2-4), Rhamnus 322 (Plut.: Phocion 25.1-2), and Lamia 322 (Diod. 18.15.1-4; Plut.: Phocion 25.3). (As noted, the heavy infantry manpower estimates related to these actions are speculative, drawn both directly from the literature as well as reconstructed from logical extension of other data.)

Also, I can add one stray obervation to Craig/Astiryu1's question about mixing arms. Nicholas Sekunda in his Hellenistic Infantry Reforms in the 160s BC (2006) has an excellent appendix (A, p. 117-124) on "Evidence for Roman Influence on Hellenistic Armies before the Third Macedonian War" which discusses the idea of mixing arms in blocks of troops along the phalanx (i.e. alternating sarissa-armed units along the front with spear-armed units or some other more mobile troop type) to create an 'articulating phalanx'. This is a tactic that he attributes to Pyrrhus in his Italian campaign of the early 3rd century, with later usage of much the same approach by Antigonus Doson at Sellasia (222), Philopoemen at Mantinea (207), and Antiochus the Great at Magnesia (190). I believe that Hannibal Barca, who rated Pyrrhus as the greatest general of all time, probably employed a similar arrangement against the legions in the Second Punic War. It's not really Craig's alternating ranks, but does seem to be a documented tactic at least rougly along the same general lines (i.e. a more versatile phalanx with mixed arms). - Fred

[Paralus]

The Pergamum shield matches the description in the manuals.....

The shields in question are the deeper bowled version carried by a phalangite that Ruben has noted plus the other deeply bowled "Macedonian shields" on the balustrade.

[Paralus]

This is a tactic that he attributes to Pyrrhus in his Italian campaign of the early 3rd century, with later usage of much the same approach by Antigonus Doson at Sellasia (222), Philopoemen at Mantinea (207), and Antiochus the Great at Magnesia (190).

The account of Magnesia clearly has the phalanx - Antiochus' best troops - blocked in the centre of the field in divisions 10 x 32 deep. I do not believe they were alternately brigaded with other forms of infantry rather with elephants. Both Livy and Appian report this (though Appian errs with "22" rather than 2). One hardly thinks this a tactic conducive to articulating the phalanx. Indeed, shorn of its cavalry, the elephants contributed to its demise.

[Astiryu1]

Cool! the "Articulating Phalanx" made sense to me because of the close in weaknesses of the Sarissa. Even though it is different from my theory I thought something may have taken place like it. I will have to look up more of Nick Sekunda's work. Thanks for the reference.

Would there be a specific troop type or types that would be mixed in with the Sarissa men? Or is it an unknown/undocumented element? This seems most interesting to me...

[PMBardunias]

But the shield on the Pydna monument has a central porpax, perhaps even off-centre, but away from the antilabe side of the shield. Are you suggesting then that the soldier would adjust his porpax mid-battle? Or is the soldier on the Pydna monument a non-phalangite with a different kind of shield? And for larger shields, I would imagine that porpakes might have to be moved a fair distance off-centre. Have tests been done on how this affects the abilities of the bearer to wield it effectively in close combat?

Actually, I did not want to muddy up the waters of the discussion, but one thing that becomes clear from the diagram I did above is that the Porpax should normally be off-center away from the antilabe in order to distribute the weight most efficiently to both sides of the ochane. My guess is that the unbalance is not too bad with a central porpax, and of course the ochane can be set off center as well.

The pydna warrior is not a sarissaphoroi in my opinion- no ochane in any case.

That thread I listed above devolved into a discussion of off-center porpaxes on aspides. One benefit of an off-center porpax, is that as with my diagram above the overhang to the left causes the aspis to pivot on the elbow joint, the left pulling down, actually helping the hoplite hold the shield level (a notorious difficulty).

I don't envision the telamon being used to support the sarissa's weight - as you state, pikemen since have functioned just fine without such support. And Plutarch's (or rather Phylarchus') words are quite explicit: Cleomenes taught his phalangites to bear their aspides with ochane instead of porpax. The strap replaced the porpax as the primary means of supporting the shield's weight. The telamon therefore supported the shield's weight, the loop placed where the antilabe was was used to maneuver it, and the arms bore the weight of the sarissa.

Then why put the wrist through a loop at all? You could simply let the shield hang while using the sarissa and then grip it with a central handgrip for close combat- those Urartian bronze shields may have been used this way. Also, in the diagram above the porpax is not supporting the shield, it is in fact pushing the shield down now as the arm is made to bear the sarissa's weight. Only the ochane supports the combined weight of arm and sarissa and shield.

And why must there be a reason that they used their shields other than as a big hanging pectoral? For the majority of the men behind the front ranks, that's probably all their shields ever did, anyway.

Because a pectoral is much cheaper and much more comfortable. You may as well just strap the pelta to your chest at that point, then you know it will be covering vital areas when you need it.