The point is, the GB 3-4 is different to our 3-4, and besides everything, we've played mostly 4-3/4-2-5 this year. And we're still a 2 gap team no matter the formation. Unless you have a crystal ball, no-one can accurately predict what effect his presence would add.
As for Maualuga, I was a big fan of his in College, but as his final year wore on and teams began running right at him and throwing in his area, his deficiencies began showing up, and he showed off his lack of physical and mental attributes at the Combine. MIT student you don't need to be, but having more intelligence than a Coke machine would be nice. And he's started because the Bengals had no-one at SLB. No-one. And even then he's lost reps to Brandon Johnson because he's awful in coverage (as too is Johnson).
If I'm taking any of the USC boys it's Cushing, because he's shown he can plug the run, rush the passer and drop into coverage.
But what are these huge problems we've got? Last time I looked we were 10-5, not 5-10, we had the number 4 scoring defense in the entire league, and were ranked 7th against the pass and 11th against the rush. Have we got problems? Definitely, rushing the passer being the biggest one, but as far as I can see the biggest problem this team has had when it comes to losing games is actually scoring enough points in the first place.