It doesn't sound a whole lot different from a 3-4 defensive front, except for terminology. In a 3-4 alignment, you've got your DT/NT in the middle. Your two defensive ends are the size of 4-3 defensive tackles, and your outside linebackers are the size of 4-3 defensive ends. Yes, the outside linebackers are in a two-point stance at the snap and half a step off the line, but otherwise not much difference. Buffalo actually were stopping the inside runs of Tampa pretty well most of the time. Tampa was killing them on the outside all game. It's hard to see how the "bear defense" wouldn't continue to leave you vulnerable to outside runs.