This is a section from GAMETIME's post and I think its one of the most insightful posts and gets to the heart of the problem (though I dont think I would agree with the last line, also dont know the source of the research he quotes). What do you guys think :
Withers IS just as much to blame as Fickell. After doing some research, I found that they made a collective decision to have the DBs play further off the ball in an attempt to let them attack/play the ball rather than watch the play develop. This was the input of Withers who suggested they run an "NFL-style" defense on the back end that let's the DBs make plays on the ball. There's a double edged sword with this apparently. With Whither's defenses at UNC his defense recorded INTs in high teens including 20 in on season, but apparently the UNC fans had an issue with him playing a prevent type of defense later in games.
With that said, I don't think Fickell's (Heacock's) D and Wither's D meshes. Whither's D is dependent on pressure on the QB, which forces QBs to make quick decisions and throws, which plays more to the DBs playing soft because that doesn't give routes time to develop and the DBs can focus on watching the ball and ball-hawking.
Fickell (Heacock's) scheme doesn't create as many turnovers, but requires more press-man and much smaller cushion in coverage. It's designed to force more 3-and-outs, not necessarily be disruptive.
So essentially what we have is a conflict in defensive philosophy that's directly contributing to our defense getting gashed. With Withers playing the DBs so far back, it takes away the small cushions that Fickell/Heacock's D would normally have and because the Fickell scheme isn't an aggressive pressure scheme, the coverage makes for easy completions underneath.
We can't have this blend of schemes, we can only have one or the other. I'd say stick to the original Fickell (Heacock) scheme on 1st & 2nd down, then on obvious passing downs and 3rd down, run the Wither's scheme.