Metal plate beneath Linothorakes or Spolades

[immortal]

I hope you don't think that armour is meant or designed to be weaponproof ? To quote your earlier post: "..that would be silly...".

Armour, from the earliest times to modern tanks, is generally designed as a compromise between weight, protection, available materials, cost and other factors. Occasionally 'weaponproof' armour shows up ( such as Demetrius' iron cuirass, or the breastplates with 'shotproof' pistol marks from renaissance times) but these are never generally adopted.

That Greek Tube-and-Yoke armour and shields were not entirely arrowproof is shown by anecdotes such as the Spartan Callicrates, mortally wounded by an arrow in the side during the opening phases of Plataea, lamenting that he didn't get the chance to strike a blow, or the Spartan Leonymus on Xenophon's expedition who was killed by an arrow which went into the side of his body through his shield and 'spolas'.....and by modern studies such as "The Effectiveness of Greek Armour against Arrows in the Persian War" by P.H. Blyth 1977 ( now available on-line - which is just as well, as my original hardcopy is fading badly :lol: ) that shows that Greek helmets weren't 'arrowproof' either, though providing better protection than shields....

Armour studies, even hypothetical ones, should not begin from a premise of how much is necessary to totally defeat contemporary attacking weapons....

A properly made steel breastplate will stop a musket shot or crossbow bolt. the 'pistol marks' you mention were pretty common thoughout Europe as a way of showing the buyer that the armour he has been made will actually protect him. They go much further back than the Renaissance.
You are also forgetting that you would try your hardest to NOT hit any armour when striking your opponent. The chances of a blade penetrating solid metallic armour is incredibly low.

I am highly dubious that an arrow could pierce a properly made piece of bronze armour, especially to the extent that is would cause any more than a fleash wound to the wearer.
Wounds against an armoured target are usually pure luck, striking a gap between the joints in armour, an eye socket or other exposed area.

Modern firearms and body armour and tanks are not valid for this argument. Firearms are now so destructive that they cannot be practally protected against. The best w can hope for is to damage limitation.