Lose quickly? I doubt it, he may have lost his two hands, but not *quickly* Anyways, I think that he uses his four arms as a sort of surprise tactic because when he only had two, he got more menacing/cocky, so he might be better with two. And Legend, I believe Kenobi was referring to the blaster as being uncivilized, not Grievous, a little play on movies because he says in ANH that the lightsaber is more civilized.