3. Eric Bieniemy
Every year for a while, Bienemy was tabbed as one of the top head coaching candidates around, only to stay with the Kansas City Chiefs under Andy Reid. I once heard from someone who is plugged in that the public perception of him as a head coaching candidate was greater than how the league actually viewed him, and so far that's proven true.
Bieniemy moved to Washington to become the Commanders' offensive coordinator, and call plays, this season. An interview there to replace Ron Rivera as the head coach is the only interview he has had to this point. Mike Florio of Pro Football Talk reported Sunday that may change though, with other teams possibly ready to give him a look.
There were multiple reports of friction between Bieniemy and Commanders' offensive players this season. But that's easy to chalk up to players being coached hard and held to a different, higher standard than they were previously, more than a sheer indictment of Bieniemy's personality.
With the way Lions' players have responded to Campbell and the culture he has installed, maybe Bieniemy would have fostered complete buy-in too with a tough coaching style. But the right choice was ultimately made to hire Campbell, and the rest is history over the last three seasons.