Personally, I find them to be a serious annoyance, but little else, except in stealing the cabal item. You can't give cabal items to any other mobs in the game, why not let that theme hold true here, where the nightwalkers aren't worthy for the Scepter if they steal it? That way, if you manage to raid, but no way to area-attack/see hidden, you still can at least walk away with the Scepter (So long as no random Scions grab it before you do, which I think is fair enough).