If we should go into next season with Porter, Willis, Crowell, we would have a pretty big improvement overall in linebackers. If McCargo picks up the slack at DT and Thomas or Youbooty fills in for Nate (remember a high quality front 7 in a cover 2 and you don't NEED a shut down corner like Clements...we'll be MUCH better than average as a defense.
If we get Okoye...it might be a finger crossing situation to pick up an inside linebacker...but we'd have a killer defensive line.