Or they can go 5 d-lineman with 2 traditional LBers and have the d-line on the end stand up and mimic LB stuff. You have seen that with both Hubbard and Hendrickson on occasion. Hubbard had a huge sack and almost a safety in the Raiders playoff game last year from basically a middle LB type position on the field.
The 2 LBs on the field in LouA's system have to be able to cover and come up and tackle well in the run game. The guys they have are good in that role.