Originally Posted by Jetworks
I appreciate the thought and effort put in by the OP, but the personnel on the defensive side of the ball are ill-suited for a 4-3 as put forth. Mo and Coples are DEs for a 3-4 straight out of central casting, but you could play them inside as 4-3 DTs, however, you are giving up a lot of weight if you start both there. David Harris is best suited to Scott's current role in a 3-4, taking on blocks to free up the flow MLB. Solo as a MLB in a 4-3 he is glacially slow.
I think Mo could hold up on the inside in the 4-3 but Coples would be more of a "tweener" and would get swallowed in the run game. We would still need an edge rusher like Abe. Maybe Coples could be that guy but he looks better rushing from the inside.
Harris would be an even bigger liability in pass coverage than he is now and I am not sure if he is a sideline to sideline LB so we would be vulnerable against the run too.