While I'm not a big fan of Nick Saban, I do admire what he does as a coach both on and off the field. NOBODY in the coaching profession has done anything close to him in rehabilitating "problem" coaches. He has given several coaches a second chance after they were cast aside for a wide variety of issues at their former universities. Most seem to have come out of their Bama "intervention" as much better coaches (and persons) after working for the "master". Kudos to him for trying to help some fellow coaches who had some career ending issues.
If it comes to pass, hopefully Butch will learn and prepare himself to be a better coach on down the way. Unlike a lot of Vol fans, I appreciate his effort at UT. He embraced the traditions, and, IMO, did his best to put good football teams on the field for the Vols. Unfortunately, he was in over his head. If he gets to work for Saban, I have little doubt that he will be better prepared if he gets another head coaching chance somewhere down the way.
I'm not big on calling anybody GOAT due to the differences in various time periods that make it pretty hard to compare. But, there is no doubt that Saban is the greatest coach we have seen in modern times.