Not sure if I agree here. Muschamp was certainly a high-prestige coordinator whose prestige easily carried over to his new head coaching position. Same thing with Miss. St's coach who is already being talked about for other, even higher head coaching positions.
In fact, in this day and age of multi-million dollar contracts and TV-contracts, I think more and more HC's are hired from OC/DC poistions already carrying our video-game's 'high prestige' concept. IMHO, the 'taking a chance on potential' ideal has declined as more schools are looking to not skip a beat, not wait for a new HC to mature. They want to win yesterday, not in a year or two, hence, "let's hire a high-profile HC/OC/DC."
Just my thoughts and opinions, though.