I'm sure someone can find an example but I'm struggling to think of a power 5 coach who left then came back to the same school to recapture the same success in bball or football. Think be easier at a non power 5 football or mid major b-ball for the coach who took bigger job and flamed out to go back and recapture the magic. If and big if he went back to ISU think he would do well but not sure he could be as successful since so many schools use is grad and transfer model now.
Difference between Fred and Prohm is Hoiberg's transfers were head and shoulders better than Prohm's, minus Shayok, and his best recruits stayed 4 years (ex. Niang & Morris) and weren't leaving at such a high rate like Prohm's who transfer out or 3 guys who left early to go pro. Good example his soph. and junior class of 4 recruits each only 1 player is left from each and both are bench players. Be very interesting to see of the 5 freshman on this roster how many are still there this fall.
The ones I can think of off the top of my head ...
Bill Snyder (Kansas State) and Mack Brown (UNC) in football came back to coach and 2nd term. Not sure on recapturing the magic.
Lou Henson (New Mexico State) returned in basketball. Yes, not Power 5.