Sounds kind of complicated. If you're going PVP, why not simply require opposed rolls? It might take some adjudication, but still seems easier to resolve. E.g. if the Brute grabs the Skulker, the latter can no longer throw knives, and has to roll using their own Brute attribute, which is presumably inadequate. Got to be clever!
(Sorry to necro this thread, by the way, but it's not exactly noisy around here; hope that's all right.)