Two "full" divisions within a conference. No crossover games whatsoever in Football.
So basically a partnership between two conferences.
I don't think it's a bad idea, but it would be interesting to see how it would play out.
You would NEVER see someone in the other "division" unless you got to the Conference Championship in football. It would make basketball scheduling really interesting and varied though. That removes a large number of teams you previously had a relationship/potential rivalry with.
Who else would the Big 10 add in your scenario? Say you got your dream scenario and added Notre Dame and Oklahoma.
They'd likely split the conference into East and West, right?
Move Purdue to the East where they belong and Notre Dame ends up in the east as well so you'd have:
East:
Indiana University
University of Maryland
University of Michigan
Michigan State University
Ohio State University
Pennsylvania State University
Rutgers University
Purdue
Notre Dame
West:
University of Illinois
University of Iowa
University of Minnesota
University of Nebraska
Northwestern University
University of Wisconsin
Oklahoma
Unknown 8th Team
Unknown 9th Team
Who's going to be the 8th and 9th West team is a HUGE question.
Also, Iowa would rarely play tOSU, Michigan, Michigan State, or PSU again unless they consistently win the West and would never play more than one of them in a season ever. Illinois would probably never play an East team again.
To me that just doesn't seem like a conference anymore and definitely wouldn't feel like the Big 10.
You always run into the issue where one "division" is not as good as the other and a valid argument from the second best team in the dominant division stating they are more deserving than the other division's champ.
On top of this, the Big 10 and SEC swallowing up 8 more P5 teams throws the rest of the P5 into utter chaos. It might be financially beneficial to the Big 18 and SEC, but it's a nightmare for everyone else. You'd think someone with clout in the NCAA or US government would flip the **** out about this.