Let's say you are correct.
I think eventually 72 teams could become a single organization of 4 18-team "P4" conferences.
We might be getting close.
If the ACC added UConn + ND (FB too), ACC=16
Big Ten = 14
SEC = 14
Big XII could add 4 for 14
PAC-12 could add 2 for 14
Who should the PAC add ? BYU and CSU might be prime schools in their region, in addition to Hawaii, Boise St., SDSU, Nevada, UNLV, and New Mexico.
They are sitting calmly back, and should hope the Big XII doesn't encroach on their future prospects.
I think the ACC should invite UConn NOW.
So who will the Big XII take ? Cincy, Houston, Memphis (?), too bad they passed on Louisville when they had the chance.....
I just wish they would hurry up and make up their minds....
I don't think Notre Dame needs to join the ACC in football. They potentially can play themselves into a cfp spot without the ACC. With the 5 guaranteed ACC games a year they just need to schedule 3-4 p5 games a year. I'm under the assumption that byu isn't joining a p-5 so they would be a potential game a year.
Personally I'd take Memphis, Cincinnati, CSU and Tulane if I was the big 12. You stick Tulane in the south with the Texas and Oklahoma schools. While sports wise Tulane is a bad pick they will be a easy conference win for the south like Kansas will be for the north in football.
For the pac 12 I would pick New Mexico and UNLV. The reason for Unlv would be to even out the north. Utah and unlv will go to the north in football. I don't see Boise State or byu as good adds.
NMSU fills up New Mexico spot. Denver could fit in as a non football team.
The main concern if the AAC expands or breaks apart. The mountain West may be able to pick up Houston from the AAC under my idea though I'll admit it's likely that they will become a p-5 school.
Should they survive then they may pick up southern miss or Louisiana Tech. They probably will add umass and maybe pick up either old dominion or Charlotte. Maybe add both and remove Navy's football only agreement.
C-usa adds 2 Sun belt teams to get back to 12.
The Sun Belt adds Liberty and Eastern Kentucky to get to 10. It may not be worth it though to 12. Though some in the p-5 may want them to expand to 12. This would be to purely give them more teams to beat up on without scheduling a FCS game.