2. Bill Belichick, former Patriots head coach
Despite the fact that Bill Belichick, one of the best head coaches in NFL history, was a free agent, he wasn't in hot demand this past hiring cycle, getting only an interview with the Atlanta Falcons. It's a bit surprising that he didn't get nearly as much attention but you could also argue that the Falcons got it right when they hired Raheem Morris. Going back to the "Hoodie", he can afford to take a Sabbath year and recharge his batteries before getting another job. Similarly, he can be picky with his options.
Even though Belichick was bad at identifying talent in the draft, he was a heck of a defensive mastermind, even in his later years with the New England Patriots. Although he had depleted the team of playmakers, he had his players working hard. It's fair to assume that if you pair him with a general manager and split his responsibilities, he'll have more time to focus on the coaching side of things, and he could be even more productive. At 71, he's still got a bit of gas left in the tank.
In fact, a bigger factor that prevented Belichick from getting a job this year wasn't his age but rather his interpersonal skills, which are essential to coaching in the NFL. Tom Brady Sr. said as much during a recent podcast appearance. But even then, he would still be a huge upgrade in Jacksonville. Of course, he would have to look for assistants outside some familiar faces. Bill O'Brien, Romeo Crennel, Matt Patricia, and Josh McDaniels have crashed and burned.
Add the fact that Belichick may not be willing to relinquish personnel control and he may not be an optimal option. An All-Time great coach? You bet, but there's more to winning than just being a coaching legend, and it's uncertain if he'll adjust his process in the future. On the chance he does, the Jaguars should then not cross him off the list.