He plays the same position, technically, but he plays entirely differently. He really strikes me as more of an Allen Iverson type (only slower/taller, with a much better shot and shot selection). He runs everywhere, doesn't play great man defense but really creates havoc with steals and jumping passing lanes, and he takes big shots. You don't want a whole team playing that way (see the Denver Nuggets), but one guy playing that way can be really useful (see the Sixers finals team).
Roy is slow, methodical, has a great handle and uses that and his power to get by opponents.
Rudy is fast, frenetic, has a mediocre handle, and uses his great shooting ability to set up his penetration.
The only real similarities in their game is that they both are listed at shooting guard, they both are known for good court awareness and passing, and they both have no problem taking big shots. Those aren't the kind of overlaps that tend to conflict much.