I agree with the schedule aspect. There are easy ways to "game" the RPI. Look at the SEC Conference; hired a consultant who used to work with NCAA and now the conference RPIs are much better ---- without playing many other PowerConference opponent.
I disagree that it cost Michigan 2 seed lines this year, though. This was a team that was trending in the 7/10 or 8/9 matchup all season. If the B1G Finals were yesterday, and the OOC slate was scheduled with fewer 200+ RPI anchors, maybe the seed could have been nudged up to a 6.