Most teams run a personel of 3WR, 1RB and 1TE. In order to match up with that personnel, we counter with a 4-2-5. If we use a 4-3 defense, they get a mismatch with the slot receiver.
We only use a 3-4 if the opponent lines up with a FB or 2 TEs.
When we had Cravens, we could line him up at LB and he could cover the slot or the TE, we dont have a linebacker like that on this team. When we were able to put our 3-4 defense on the field, we played the run and pass pretty well last year. But we rarely had that defense on the field.