Well, the ACC is the next step. Some coaches go from Boise State to Auburn for example. The jump is not the problem. There are a lot of coaches who have started at low tier programs being the head coach. In fact, at those lower tier programs, I can guarantee you you might learn a thing or two more about team cohesion, getting coached up well and scheming well compared to a program that is more talented than others but fails to meet expectations all the time.
Urban Meyer was the HC at Bowling Green, went to Utah and then went to Florida. Nick Saban was the Head Coach at Toledo at one point. Heck, Mario coached at FIU as a HC and now just upset Ohio State with Oregon. Matt Campbell coached at Toledo as well, went to Iowa State and turned that program around. Being good at a low-tier level with a team that isnt supposed to be that good at that level is a really good sign that the head coach in question is good.
Dont hire a coach because he just coached at high level programs. Hire a coach based on his successes and failures given the circumstances that he was dealt with.
Both Clark and Chadwell are overperforming with their teams based on the talent they have and the circumstances they are under. The fact that Grayson McCall, a two star-prospect being 20 years old, is capable of executing a more complex option offense compared to the stuff we run with KIng at a much higher level speaks volumes for the player itself, the players around him and the coaching staff coming up with the scheme and preparing the players.
Both guys would be massive upgrades compared to Manny. To me, thats not even worthy of a discussion. You eiher hire these two or an assistant from a top level program who knows what a top tier college football team should look like.