Conferences really need to go to 3 or 4 divisions at this point. You cannot have all these name programs all be successful at the same time.
The SEC will have UGA, Tennessee, Florida, Bama, A&M, Auburn, LSU, Texas, and Oklahoma. With zero divisions you have 9 teams fighting for 2 spots. With 2 divisions you have 5 teams fighting for one spot and 4 teams fighting for the other spot. With three divisions there is fewer teams fighting for that one spot, and you can have a WC slot. So you are looking at 2-3 teams fighting for one spot in each division and then 3-4 teams also fighting for the WC.
Edit
So for the SEC to have 3 divisions they need to add 2 more teams. Geographically it makes most sense to add Okie State and NC State. That way you can have 3 main programs in each division.
East- UGA, NC State, Kentucky, Auburn, Florida, South Carolina
Central- Bama, Ole Miss, LSU, Miss State, Tennessee, Vandy
West- Okie State, Oklahoma, A&M, Arkansas, Texas, Mizzou
So this year you would have an SEC playoff of:
1. UGA vs 4. Oklahoma
2. Bama vs 3. Okie State
With 2 divisions at best only 2 of the 9 main SEC programs can have success in a given year. With 3 divisions and a wild card, at best 4 of the 9 main SEC programs can have success in a given year.