You basically never see power 5 coaches moving from one school to another if they are successful they tend to stick in place. Almost every hire is a guy who is over performing at a Cincinnati, Memphis, Boise, San Diego St etc etc. If not that, they are a high performing assistant. Then there's the rare case of getting someone from the broadcast booth like Meyer or from the NFL like Saban/Harbaugh.
You have to pounce when guys like that come available. So you pretty much make Chip Kelly say no if Butch is fired. Kelly managed to have back to back 10 win seasons in Philly, his leaving there was more conflict with the front office. San Francisco was just a mess. His record at Oregon was awesome and he left enough talent there for Oregon to go 33-8 the 3 years after he left with a playoff win and championship game before things fell apart.
Before anyone starts with the SEC smashmouth rah rah nonsense, from 2000-2017, the very height of the SEC's power, the conference record vs the Pac 10 is something like 15-14.