Armor&weapon Salvaging?

What if thieves could be sent into battle to salvage armor&weapons from dead units, enemy and friendly. The armor&weapons they bring back can be downgraded because it's already used. But the armories and smiths can be given an option to repair weapons&armor. Or troops can be sent into battle with more than one kind of armor. Or both. It's mostly to clean up left over amror and weapons because it piles up...