He's not talking about stats the way I think of them. He's talking about recruiting rankings and record predictions based on those. We've heard about the effect of coaching as well, when it comes to talent comparisons and game/season outcomes (W-L records to be plain). I think you'd look at the purple wizard and say his coaching gives you an extra win per season or whatever...
I think it's very difficult to assess conference strength when there are so few out-of-conference games between P5 teams. Considering how early in the season these are, too, means we can't draw too many conclusions from them...and it's the same thing with the bowl season (for different reasons that I'm sure anyone reading this has a good idea about already). Until we have the best teams from all conferences regularly playing each other, it's all BS to me. I'll play along, though, for the sake of this discussion...
My favorite strength of schedule (SOS) calculation comes from footballperspective.com but I sometimes do my own dumb calculation, too. You can find an explanation of how I average a number of z-scores across nine categories to determine team rankings in the posts I start on here. If I take the average of every composite z-score for every team on the two schedules in question (ours and Tennessee's), weighted for SOS using footballperspective.com's ratings, I come up with 0.0133 for NU and 0.226 for UT. That's surprising to me because fp.com has the SOS ratings for NU and UT rated as practically even. To put that in terms that are easier for all of us to understand, the average percentile rating of the (stats for the) teams on their regular season schedule comes out to be 59 while the calculation for Nebraska's average (fictional) opponent is 51.
I went and looked up recruiting rankings over multi-year periods and came up with this:
http://www.sbnation.com/college-football-recruiting/2015/2/6/7987571/recruiting-rankings-ratings-2015-college-football-teams
After looking at this, it appears he's actually being generous by saying the average ranking for the B1G falls between those for Mizzou and Vandy.
Now, if I take fp.com's stuff out of my calculation entirely, I come up with: -0.02 and the 49th percentile for the good guys; and 0.27 and the 61st percentile for their bowl opponent. The teams they've played have put up better numbers relative to national averages. Is that because they're more talented? If I look at how the average stats for the SEC and B1G compare to national averages, the numbers actually work out to be the same if I consider all categories (though B1G defensive stats compare more favorably and B1G offensive stats compare less favorably).
If I consider the average ranking I calculated, with the SOS adjustment, and figure a standard deviation above or below for the cutoff to determine what teams are bad or great...I find the B1G has three bad teams and three great teams. By the same rationale, the SEC has no bad team and three great teams this season. In terms of overall stats, though, the SEC has more teams with below average statistical rankings (relative to national averages) than the B1G: that's 8 to 5 in our favor. Fp.com gives the B1G a slight edge in terms of the average conference team's SOS as well.
TL; DR? I don't blame you but, seriously, there are real numbers behind what the dude's writing about. They just don't tell the whole story or college football would be rather dull.