So, what WAS the armies' leather armor made of?
Obviously it wasn't from some mythical beast, but it WAS something different, to take Tydus's axe hit and not sunder.
shareBy all accounts I have heard or read leather armor if treated right could provide surprisingly good protection even from metal weapons. Its advantage was it was light, cool, and cheaper than metal. The disadvantage was it didn't last as long and didn't always provide as good as protection especially as metallurgy advanced. It was popular in many cultures up to several hundred years ago.
One thing the movie didn't outright emphasize was Greece was more advanced than Thrace especially in all things military. That is one major reason Coyts needed Greek mercenaries to train his army.
The link below provides a good overview of it:
https://www.youtube.com/watch?v=KUPIUHpkK88
Greeks always feared Thracians. Thracians were known for being a militaristic people. The Greeks perhaps introduced hoplites to them, but that is all. Without their Thracian neighbors, the Greeks would have no peltast javelin throwers or cavalry.
The Thracians didn't use as much armor because they preferred mobility. In terms of weaponry they were perhaps even more advanced. I do not know of any Greek weapons that are composed of as much iron as the rhomphaia. The Greeks just used spears (nothing wrong with that, it's actually much under-rated in relation to a sword), and swords that topped off in 20 inches length (if not less than that).