I have to disagree. When he gets out on a switch you can tell he doesn't know what to do. He gets happy feet and starts doing the thing where he's moving in place. He gets turned around and wrong footed so much, and I'm not convinced it's because of his foot speed. When Rudy is in the paint, he can rotate his body in a cone super fast and defend multiple actions in different directions. It's because he knows what to do and has good instincts.
He doesn't know what he's doing out there. It makes sense because it's not something he's ever been asked to do in his career and probably didn't practice it much. If he works on it, he'll get better. This is where Rudy can look at Stevens Adams for inspiration. Adams was a total goof on the perimeter early on in his career, but he was able to stop us over and over on switches in the PO's because he made it a point of emphasis and developed those fundamentals.