[quote=IncredibleBee]
If you really want to get down to it, there are numerous armies that fought with little to no armor. Greeks, Romans, a lot of barbarian tribes from around that time, off the top of my head.
[/quote]

Yes. Using light armor against light(er) armored troops =/= using light armor vs heavily plated knights with giant swords. Comparing sheep to cows.

[quote=IncredibleBee]Even after heavy armor was developed, the poorest foot soldiers had little in the way of protection besides what they could loot, sometimes nothing at all.[/quote]

Guess who suffered most of the deaths in these armies.

[hider=answer]Not the heavy armored troops.[/hider]

To kill a plate armored soldier you had to use either blunt weaponry or survive long enough to get lucky and be able to knock/pull him down and stab him where it hurt. Hitting the joints of their armor was practically the hardest thing ever and was mostly dependant on luck in actual combat.

[quote=IncredibleBee]Also, Musashi defeated an expert martial artist with a wooden sword. Regardless of his intention, the fact that he used a wooden substitute MAKES it impressive. It's indicative of his skill as a high caliber martial artist.[/quote]

Musashi knew he wasn't going to be able to defeat him conventionally, so he arrived late + fought using a wooden sword fashioned from a paddle. He infuriated his enemy. It had nothing to do with light armor vs. plate armor which we are discussing. IDK how this relates to what we are discussing. Yes it is impressive. It doesn't make him a better swordsman though, it simply shows he understood how combat works.