I'm of the opinion that Mike Nolan had a lot to do with our defensive success since he arrived. Nolan is gone and even in a 3-4 our defense would suffer IMHO. But, we did play a hybrid 3-4 / 4-3 even last year. Wake played a pass rushing DE in a 3-point stance quite a lot last year. The scheme change will nothave as muchof an impact as the personnel change and coaching staff changes though IMHO.
Soliai is good, but too expensive. Bell is past his prime. We lack turnover makers. We need at least one more good pass-rusher. Our LB corp is weak, regardless of what anyone says. Dansby woefully underperformed, Burnett is journeyman quality, and Koa Misi is a bust. (I was screaming at the TV for us to draft Gronkowski, but we HAD to have a non-pass-rushing LB, I was soooo pissed off). Our only real strength is DL, where Starks, Soliai, Langford, Odrick,and Merling is an embarassment of riches. The 4-3 leverages those riches and helps with the acquisition of talent.
One of the 3-4's main advantages used tobe the valuable pieces like tweener hybrid DE/LB were easier to find than the true 4-3 DE. With today's NFL having so many 3-4 teams, that advantage has disappeared. We are well placed to switch to a 4-3. I just hope we can produce more turnovers and find another pass rusher.