The Abandonment of the Gladius for the Spatha - Why?

[Tarbicus]

I suggest you visit italian museums where you can see etruscan and pre-roman swords relatively longer than the gladius.

Absolutely, I know about them, and the early gladii that could be as long as 76cm. But that isolates taller latins as being the mainstream, whereas a more overall view would see the army as being generally shorter. Dismissing the idea that the Italians can't have adopted short swords because some recruits were tall is similar to saying that rifles should eject empty cartridges to the left because some modern recruits are lefthanded. Armies don't work like that; Lefties are still recruited, and if they have a problem with it they'd better learn and train harder, because this is how the Army does it.

We know that commanders and the men were willing to try knew things, and if it was realised that there was more success with "this" method than "that" they would surely continue to use the successful one. I doubt they said "We're shorter so we need to start doing this." But after a battle won no doubt they discussed it afterwards, coming to some logical conclusion.

I dare say that the whole method of group combat and weapon type was influenced in some way by stature; not wholly, but to a degree. Adopting the low crouching stance behind the large shield with a "stab, stab, stab" technique within a usually taller opponent's reach transforms the percieved disadvantage of height into an asset. To me, the most telling thing is that as recruits gradually consisted more and more of past and taller enemies the sword also gradually, with a fully logical delay, grew longer again.