SKel:
I will first try to get all the unit's done and playable, then maybe look in to this later.
You have right.
I think the mod should be playable at least as a beta. Even if you use bad skins because we can test the AI behavior and the problems early. This way the skinning and the writing-calculating processes can go in parallel.
Than you can add the correct and refined skins to the game with patches. IMO

if they didn't belive in going to combat with any armour, why then bring a shield?
I think their naked fight has cultic origin.
I like the idea of evolution. In the eary times there were berserkers with a single weapon and others also weared shields. Their first battle showed the evolutionary advantage of using shields. The single weapon-type berserkers had no chance making children and transmite their blindfold behaviour.

Althrough I understand your situation I was also in big trouble to find out what the old Magyar warriors should wear.