Need some information about Mantinea 207 BCE

[D B Campbell]

Polyaenus' anecdote is most likely the second one(a major defeat)

"Most likely" in who's opinion, Paul?
All Diodorus says is that "Onomarchus defeated him [viz. Philip] in two battles and destroyed many Macedonians" (35.2).
Why couldn't the cul-de-sac incident be the first of these? Oh, I remember ...

immediately after this encounter, the Army's reaction was to refuse to take the field

You've postulated that the Macedonians were so shaken by their first experience of catapults that they immediately mutinied. So it would be rather inconvenient to your theory if this were actually the first of the two encounters, rather than the second and final one.

So no 'yarn' then, Duncan, rather reasoned logic based on fact and the sources! 8)

Actually it's your interpretation of the sources, Paul.

Unsurprisingly, Onomarchus lose the final battle (Crocus fields) and is killed(354/353/352 B.C. ) ... Onomarchus was not given the opportunity to draw Philip onto a pre-prepared battle-field, with catapults emplaced.

Because that would've been the natural thing to do? "If only I'd had my catapults", groaned Onomarchus, as he fled the battlefield. I don't think so!
None of this supports a case for Onomarchus having artillery, which is what you'd like us to believe.

Philip's reaction was to take an immediate interest in Artillery ... ... after his encounter with Onomarchus and the Phocians, Philip employs a famous catapult engineer, Polyeidos, whom many think invented torsion artillery while working for Philip sometime in the period 353-341.

Strike two!
No ancient authority calls Polyidos "a famous catapult engineer". Marsden suggested that Polyidos was probably linked with the development of the torsion catapult, but it's a theory. (I presume that, by "many", you mean those authors who accept Marsden's suggestion. Hammond and Griffith spring to mind; but they're not "many".)

You are maybe hoping to persuade people of a causal link between Philip's defeat in the cul-de-sac and his hiring of Polyidos. Hence the "immediate interest in artillery". So you suggest that Polyidos could've been hired in 353. But Marsden (and it's pretty clear that he's your source for all of this) suggested 340 at the earliest. (And of course, there's no guarantee that Polyidos had anything to do with catapults. Only a theory.)

His formidable artillery quickly overcomes Perinthus,in 343/342/341

Perinthus won that one -- Philip went off with his tail between his legs! :lol:
What happened to "fact and the sources"!?

(D.S.XVI74.3 "The King for his part rained destruction with numerous and varied catapults upon the men fighting steadfastly along the battlements, while the Perintheans, although their losses were heavy, received reinforcements of men missiles and artillery from Byzantium"...and "D.S. XVI.75.2 " his catapults cleared the battlements") despite them being aided by Byzantium ( which he also besieges) and being helped and supplied by Persia itself.

Now this really is irrelevant.
You're trying to prove that Onomarchus had stone-projecting catapults in "355 ,354, or 353 B.C." by pointing out that Philip had arrow-shooters in 340 BC. Where's the "reasoned logic"?!

... the non-torsion stone-throwers in question were no longer than 1.25-1.5 metres long, with a bow-span of a little over 2.5.m, mounted on a small stand.....so not so big, but still static, not mobile.....

That's your opinion. Let's separate out "fact and the sources".
Polyaenus mentions "stone-throwers" which I think are men and you think are machines. That sounds like "opinion" to me.
Sources? Well -- again, you haven't cited any, so we don't know why you think that Onomarchus had machines "no longer than 1.25-1.5 metres long, with a bow-span of a little over 2.5.m, mounted on a small stand".
(Why do you think that?)

It is a bit difficult for me to imagine lots of clumsy machines in a roadless hillside, used as early mountain artillery.

That's a very good point, Wolfgang.