Armour in vanilla how does it work?

I've been playing for quite a while now and something has always bugged me about the armour upgrades. For example when I give viking raiders chainmail armour they should have the same protection as huscarls right? Then why do the stats say they have 2 armour while husscarls with the same armour have 5 armour. I tried rationalising it for a bit with "maybe theyre lower quality" but thats a bit of a stretch.

Does the armour type or the armor stat count? It would be lovely if somebody knew and could tell me.

Verstuurd vanaf mijn GT-I9515 met Tapatalk