With all three returning starters back from last season the linebackers were already going to be the strength of Oklahoma's defense but now that Frank Shannon has rejoined the team OU should have the best group of `backers in the Big 12 and one of the top in the nation.
If the Sooners do, in fact, shift back to a 4-3 front then they'll have an extremely difficult time deciding which of the four guys sits as a "rotation guy" and which of the three would serve as starters. Should the stay in a 3-4 then they will have the talent, and aggressiveness, to attack down hill.