After 30 seconds of looking at it, the problem with their SOS metric is that it says it's based on what winning percentage a top-5 caliber team would have against our schedule, but top-5 caliber teams would have a better record in a "hard home game, less hard away game" scenario, but moderate-to-bad teams do better with "hard away games, less hard home games" because the "less hard" games are the only ones they'd have a chance in anyway.
Our schedule is harder than a team like Vandy (Auburn and UK at home next year). Florida's is hard, but they get us at home. Oklahoma gets Auburn and LSU at home. Our home games are Texas, UGA, Tennessee, and Ole Miss. It's very, very likely we don't win an SEC game with that schedule. For a moderate-to-bad team, I think our schedule is the hardest in the country.