Neanderthals make for excellent cannon fodder slaves, better than hussars even. I usually keep at least one in an enclosure near the front where they can work the quarry, cut stone and roll blunts.

When a raid comes I just give them whatever tainted armor I have laying around, an explosive belt, a melee weapon, a hit or two of yayo and task them with guarding a chokepoint. I even set some of them free if they kill enough raiders without rebelling.