This is what I'm doing in my current dynasty. I have the SEC and B1G as 14-team conferences with the other 8 as 12 team conferences. Army and Navy are the only two independents.
This is my conference order and reasoning behind it:
P5
1: SEC. Added two schools (Texas A&M, Missouri) from current P5 conferences and lost 0. SEC is #1 because of stronger teams at the top.
2 (1B): B1G. Added two schools (Nebraska, Maryland) from current P5 conferences and lost 0.
3: Pac-12: Added one school (Colorado) from current P5 conferences and lost 0.
4: ACC: Added 0 schools from current P5 conferences and lost 1 (Maryland)
5: Big 12: Added 0 schools from current P5 conferences and lost 4 (Texas A&M, Missouri, Nebraska, and Colorado).
G5
6: American: Lost 3 schools to current P5 conferences (Rutgers, Louisville, TCU [TCU left the MWC for the Big East, but joined the B12 instead] as well as all the former Big East schools in the ACC as well as West Virginia).
7: Mountain West: Lost 2 schools to the current P5 conferences (Utah, TCU [counted twice])
8: C-USA: Replenished the American after their losses.
9: Sun Belt: Replenished C-USA after their losses.
10: MAC: (possibly the most stable of the conferences and hasn't lost a full member to another conference since Marshall left for C-USA).
After several years I have Ohio State, Michigan, Illinois, and Nebraska in the SEC with Michigan State joining after this season. Bedlam is played week 15 when Oklahoma and Oklahoma State are in different conferences.