So far, the only opponent better than them at avoiding that stuff is Notre Dame. And I watched 5-6 college football games this weekend and didn't see a whole lot for clean games.
USC is 4-1 and still in the top 20 but they've had issues on defense all year. Indiana struggled against Northwestern, and had it not been for a stupid facemask penalty on NU on a 3rd and 19 deep in IU's territory that was stopped well short of the first down, should have lost. Oregon lost to Oklahoma State who lost to Tulsa.
Almost every school has 1/3rd of their roster new, so it's not so much who is most consistent/clean now as it is who will get there faster.