The semantics of the 3-4 vs. the 4-3 are being blown out of proportion imo. It doesn't matter what base personnell group you have out there, you can line up anywhere you want. With our 4-3 base, our alignment was mostly a 5-2 with the SAM lined up on the LOS over the TE. The 5-2 is essentially the same as the 3-4 with 2 LB's walked up closer to the LOS.
The ONLY, and I mean ONLY real difference in a 3-4 and 4-3 is swapping a DL for an LB. And the debate and CPJ's comments were spawned by the real concern over quality DT depth next year.
Whatever base personnell you have out there, defense is still about gap control and responsibilities. In either defense, your gonna have both DL's and LB's whose primary responsibility is the A, B, C, or D gap. If they can do it in a 4-3, then they can do it in a 3-4.
My primary reason for liking the idea of the 3-4 is that, like CPJ's offense, it differentiates us slightly in recruiting and preparation. I think there is a huge abundance of DE/LB hybrids available for recruiting. We can get those guys better than anybody around us if we run a 3-4 and can say we run what the NFL runs (doesn't really matter, but could be a perception advantage). I know of several personally from my coaching days that would be perfect 'tweeners like that. Think about Darryl Roberson, Michael Johnson, Eric Henderson, Phillip Wheeler, Key Fox, Gerris Wilkerson .... All of those guys could've been great at DE or LB and have played both positions at some point in their careers.
Think about Adamm Oliver, Joe Anoai, Mansfield Wrotto, Eric Henderson again, those guys would be good as 3-4 DE's. The one position that would be a little different would be the nose and it really doesn't have to be that different. You don't have to have a Terrence Cody to be successful in the 3-4. Barnes and Lanier seem to fit that position perfectly, just based on size. Walls could probably do it. Vance and Richard could've done it fine. Both of those guys would've been fine at nose or DE I think.
4-3 or 3-4 can be successful with our players if it gets good coaching.
I loved Tenuta's 4-3 because it wasn't conventional. It differentiated us in recruiting and preparation. I still think that's what will be most successful at Tech, and why CPJ is the perfect fit here.