The OL play has been really disappointing. It was a group that returned largely intact so the regression is annoying. I will say the OL has been hit particularly hard by injuries but even accounting for that, the play isn't what would have been expected.
The area where the talent dropoff hits hardest is at linebacker. Georgia lost the best linebacker in college football to the NFL in Roquan Smith. The dropoff has been huge. The linebackers were essentially MIA against LSU.
I actually don't think the talent regression at RB is big enough to account for the dropoff in the running game. Swift is a beast and Holyfield is extremely difficult to bring down. I think the OL play mixed with Chaney's natural tendency to neglect the power run game has really hurt the ground game.