Personally I was never in the 'need to fire Whiz' camp. I saw why it could be considered necessary, but could also see the risks in firing him due to personnel issues. Late in the last season it was clear he had lost the team, but that happens to any coach after a string of bad seasons.
I was however completely on board with getting rid of Graves, and thought it was his fault things turned so sour. It's the HC's job to coach the players the GM gets. If some of this is offloaded to the HC, and those decisions fail, I still put the blame on the GM, because ultimately it's his responsibility to give the head coach the talent to win.
I don't want to fire a decent or in our case one of our best coaches ever because he failed at being a part time GM. I want to hire/fire a head coach based on coaching.
That's why I'm glad Keim seems to be a competent GM able to project, see, and make moves to keep the talent flowing. It's remarkable how many guys we picked up on the eve of training camp and throughout the season that made a big impact on how good we were as a team.
Overall I wonder what would have happened had Whiz remained and we simply booted Graves for Keim. Personally I think it could have worked. But hey, what we have with Arians and Keim I believe is superior to whatever Whiz/Keim could have done. Our defense also didn't drop off with Bowles instead of Horton.
So now back to Whiz... based on this I do believe Whiz could work some magic with the offensive talent in Detroit. He wasn't bad, he was stuck with some glaring holes at important positions, made some bad decisions, and finally lost the team. While Grimm was a sticky with Whiz here in AZ, Detroit might get Whiz without Grimm. They have a QB, an all world WR, some nice building blocks on defense, and Reggie Bush.
I don't think he'll treat Stafford like Leinart. I could see Suh or Fairley getting in his doghouse though.
As a coach with that sort of talent around him, I think he can succeed. I think such a situation is what he's tailored to do. His offense may suck with crappy parts, but with good parts, it runs (no pun intended) quite well. I definitely agree that for what Whiz needs to run his offense, Det makes the most sense.
Though in the NFL few win championships and just about everyone eventually gets fired, so who knows if he would succeed. We're just guessing what situation gives him the best shot.