I think OP missed the point, which is the last chart of overall wins - losses.
Basically, for each of your wins, you get credit for your opponents wins. Each of your losses, you get credit for your opponents losses.
Long story short, if you lose to a team with no losses, and you've beaten teams with a considerable amount of wins, ie Wisconsin 4-1 with only loss to undefeated Michigan, you're look pretty good.
This is more or less just a way to put numbers to SoS.
For instance, you have Tulsa, a 4-1 team, Their only loss comes to tOSU, so they have no losses, but they've also played trashcan teams with only 2 wins.
As has been pointed out, you almost have to go a level deeper. Because if we play a bunch of schools whose early-on schedule consist of the bottom of the FBS, we'd look really good with no losses. Yeah, our opponents are all undefeated, but that's because they've played us and the Kent States.