Browsing through I didn’t see anyone else mention this -
Raiders should randomly drop something when killed. An armor, weapon, etc. It doesn’t make sense that they came empty handed or naked to a battle.
You can use the predator carcass when you kill it, but can’t do anything with the raiders you kill.
I’m conflicted about whether or not you get anything back from dead villagers. I haven’t run perfect tests, but I think you may. Regardless, that should be a given. If the armor ain’t broke, gimme!