4. Marvin Lewis
The former long-time Cincinnati Bengals head coach, at 62 years old then, would surely have been a safe hire for the Lions over the perceived "riskier" hire of Campbell. But the build to sustained success in Cincinnati took a lot of time, and when it dropped off again the patience to have him build it again went away.
Lewis then spent some time at Arizona State as an advisor and co-defensive coordinator when Herm Edwards was the head coach. That tie seems to be leading to him coming back to the NFL with a spot on the Las Vegas Raiders coaching staff under head coach Antonio Pierce, who was also on Edwards' staff in Tempe.
Lewis is a good man and a fine coach. He will be a good hire for Pierce in whatever capacity that is with the Raiders.
But it's fair to say the game has passed Lewis by a bit, or more than a bit truly, and he'll probably never be a head coach again. The Lions were right to give him a look with an interview during the process that landed them on Campbell as the next head coach, if only on the notion he would be a calm, stabilizing presence. But they clearly had their eyes on Campbell, and ultimately weren't going to be deterred when there was mutual interest.