Wait, you're argument is that you can't tell if a 10-6 team is better than an 8-8 team because they don't play the same opponents? Not only is that a ridiculous point and a complete reach, but would divisions solve that?
So, explain how that would work, and how it would be different than scheduling without divisions?
The floor is yours.
And the 8-8 team might be better then the 10-6 team. It's called strength of schedule. It's a thing. Might want to look into it.