I don't think the JW is even remotely putting his job on the line if he extends Groce. He has so much good will in the bank with the Lovie hire he is going to be able to do pretty much what he wants for the next few years. JW will make the calculation of how much of that good will he is willing to risk, and just how big of a net risk he would be taking (in keeping or firing Groce). I don't think it is an easy of a call as some of you.
Oh, I wouldn't' want to say it's an easy call. Parting with Groce IMO would be easier than not, but either way it's a big decision with plenty of risks. The risk of retaining Groce is obvious, based on the trends in performance and attendance: he keeps losing and we're not among the top 68 teams at the end of the season. The reward is he's turned a corner with his coaching and we stop having to ride the bubble. I don't think he'll ever be an elite coach, so I'm not sure what his ceiling is. I'd put his top end below Matta, but Matta had a NC appearance when he landed one of the best classes in history. I think Groce's performance is more dependent on presonnel than most coaches, and he doesn't have the knack, at least yet, for putting the puzzle together to ensure he'll have a successful roster. I hope for his sake and ours that he's made progress. The real problem for me with Groce though is his motivational skills. He's built incredible loyalty in his players, but he doesn't seem to have that knack for firing them up game to game, or strategically through a season.
The risk of the unknown is just that, with the additional complication of who you can get, and whether any of them are what you're looking for. Although I would add that schools have lucked into good coaches more than a few times.
Btw, I disagree with the statement that he has so much goodwill he can do whatever he wants for years. Sports are fickle. A few bad breaks can change the character of narrative. It takes an insanely good saleman to turn losing into something fans believe is winning. As an example, Groce surviving 4 years without an NCAA tournament appearance would have been unthinkable to me, but it could happen.