No different than Brian Kelly going from Cincy to ND. A good coach will win anywhere.
Hard to say how good a coach he is though. He's won at Western Michigan and Cincy, but he followed Brian Kelly at both places and didn't really stay long enough to be winning mainly with his players vs. Kelly's recruits.
Petrino had no problem going from Louisville to Arkansas and winning--though he had the one partial season in the NFL in between--as well. Rich Rod struggled at Michigan, but I don't think they gave him enough time to get his system in place and all the type of players he needed to run it--took him 4 or 5 years to really get things rolling at WVU.