Last I checked Tennessee isn't in a recruiting hotbed of talent. Sure there is Memphis and Nashville, but with only 6.2M people in the state Tennessee recruits a lot in the Carolinas, Florida and all throughout the south and even nationally. What Tennessee does have, however, are big time boosters and amazing fan support. There is a lot of money in the South and there are yachts that tailgate on the river just before the game. We are talking about a river full of 40+ foot yachts. It's unreal. They fill up a stadium for a bad team at $80+ a pop that holds over 100k.
The top 3 things to run a successful program:
1. Admin support (academic exceptions, if necessary)
2. Fan support (boosters and selling out)
3. Local talent
There are other things are a factor too like campus lifestyle, cost of living, academics, TV exposure, etc... but some of these kids wouldn't be in college except for the fact that they play football (or bball) incredibly well. Good for them though and I hope every single one graduates and lives a successful life and has opportunities presented to them that they wouldn't otherwise get because they run faster than the next guy, can jump higher or are stronger/taller than their peers.
When the coach at Memphis was fired he said he wanted the admin to provide the support it needs to be competitive in their conference.
When Mac was at CU he had the full support of admin. It's no coincidence that he left when the support of the administration started to wane. I'll look up the SI article that brought that to light later.