I don't a definitive answer to this question, but I do have an anecdotal one. I'm personal friends with a number of college football coaches, one of whom won the Broyles Award as a defensive coordinator. To a man, they all told me that it will be damn near impossible for CPJ to assemble a good defensive unit (this was shortly after the hire). Of course, I asked, why?
One obvious reason given is reps, our defense only sees our offense during spring and fall camp, so that puts them behind the eight ball before they even see a scout team two weeks ahead of the first game. This gets compounded by the fact that it is very difficult to assemble a scout team that is even a close facsimile to what the D will see on game day, because we don't have the kind of players on offense that can simulate a "normal" offense. As each year passes, these words I heard over a decade ago ring more and more true...