Nah, Rose would have a similar problem with the fit if he had to defer to a Durant-esque player every night. If Westbrook was The Man on his own team, I think he'd break out of his little zone and step it up a notch to keep his team elite. There's only so much he can do with two other elite scorers on the floor with him.
I don't think Rose would struggle or be any different if he had someone like Durant, he's always looking for his Bull teammates on offense, he handles operating a half court offense a lot smarter and smoother than Westbrook, he doesn't jack up 15 foot jumpers with 22 seconds left on the shot clock. Rose is a much more intelligent and in control player than Westbrook. They are pretty equal physically but Rose is on another level mentally than Westbrook.