Hiring a head coach is a complex topic.
Off the top of my head, the most successful head coaches in the NFL over the last 15 years would be Belichick, Carroll, Payton, Reid, and Tomlin.
Seems like a good list.
Now before any of them was hired, did they run a top 5 overall offense or defense before their current open positions? (Hint, not Payton, Reid, or Tomlin).
All of them had the good fortune of having Hall of Fame quarterbacks at the same time, so, you know...
That being said, I do not know what tier I would put Justin Fields. He's a dynamic talent that could turn into a hell of a player, or he could be the dud we saw this season. What matters IMO, for a good HC, is the ability to run the team well and have a good program that works. I do not know if this will be ME, but you cannot really know who is going to be the next juggernaut HC. Most of these guys get fired relatively quickly.
So we will see. I do believe that Matt needs to build a good room of coaches that can show some improvement for the franchise. I mean, I'll pretty much take any kind of on field improvement consistently over several seasons.