I would put Greg in the "risky" category. He did wonders in getting the Rutgers football program from a laughing stock to respectable, but seemed to lack the skill set to take it to the next level. The inside scoop was that he was to much of a control freak. Leaving Rutgers (for Tampa Bay, particularly) was inexplicable. He was like their 5th choice, no one wanted the job.
Still, I would be willing to give him a try at most schools, Tennessee might be a reach, but then again, they have been little but bad in their coach hiring.