Yeah, Collins can coach a D. There is no doubting that. But his base scheme lines up poorly with the flexbone. It is kind of like Mickey Andrews at FSU. He was a great D coach. But CPJ took him to town. And the Fridge did it too running a double option with Joe.
On the flip side, you can adjust your scheme to stop the option and get significantly worse at stopping everyone else, aka the Bud Foster approach.
If you don’t want to change your D scheme, it is easier to go ball control on O and wait for your D to get a turnover against the 3o. That was Richt’s approach and it worked pretty well. Shoot, that is what LSU did in the Peach, where we got yards but no points.