Not much worse than 6-6 Oklahoma or 6-6 Vanderbilt (who both had an extra non-P4 game to help them get that extra win).
I think that’s where the 8-game schedule helps the SEC the most. Essentially it gives 75% of their teams an extra win. Losing to Oklahoma and Vanderbilt doesn’t sound so bad when you see both those teams in a bowl game. But if they had to play an extra conference game, they might both be 5-7 instead and they’re perceived as much worse losses.