If they play 3-4, I'd think it would be in passing situations, or against primarily passing teams. We don't have the players for a traditional 3-4. It would be more like a 3-3-5, with Brackens as the hybrid LB/S.
I am completely ignorant on the personnel requirements for a 3-4 defense, but looking around at a few other schools that run the 3-4, it looks like the starters that CYCLNST8 mentioned are all similar in size to the typical college player at their position. The OLBs may be a bit undersized. Backup NT and OLB look to be undersized underclassmen.
I really can't see the 3-4 working with this group. It takes a more specialized & talented player.