It's a fun thought process to come up with divisions or pods but I think it's hard to beat the division-less flex protect plan put together by the Big Ten.
With that said, if they were forced for some reason to go with divisions, how about this
West division (4). - USC, UCLA, Ore, Wash
North division (5). - Neb, Iowa, Minn, Wisc, NW
South division (5) - ILL, PUR, Ind, Mich, MSU
East division (4) - Rut, MD, PSU, OSU