Guarantee all the my old friends whining about "muh immersion" would REEEEEE like a bunch of of eunuchs if there was a malus penalty for mismatching armors/weapons from different eras and cultures.
I absolutely would want more variety from as many diff cultures and eras as possible, but I would also prefer if there was some sort of set bonus for properly matching armor/weapon pieces. If you added roman and aztec armor right now some oblivious cunt would walk around in jaguar pyjamas, roman helmet and wielding a katana.