I've often asked how long before a Blue Blood becomes ordinary. I don't know the answer of course, I have suggested it's about "five mediocre to bad coaching hires in a row". Now, I'm assuming an "Urban Meyer" type (dime a dozen) could step in and revive said program, maybe, after five bad hires. Maybe.
The Vols are not looking very good obviously, they won't fire their coach this year (probably, without cause), but they are clearly on thin ice.