Ok, so start with the easy things...
- B1G has 14 members. Kicking any out is unprecedented. Given the money, any leaving voluntarily isn't going to happen.
- SEC is the exact same.
- PAC is similar, but without the money aspect. Even so, I don't see Colorado jumping back to the B12. Utah I think likes the PAC. Unless the B12 could offer some crazy money, I see no reason why the AZ schools would head to the B12. So I don't see them losing anyone.
So you're right. If we have additional consolidation, it's going to be at the cost of either the B12 or the ACC.
The problem is that the B12 doesn't have any good targets to add. The ACC, on the other hand, could probably pull WVU out of the B12 and add ND in a heartbeat, if they could get ND to agree.
So how could the powers that be have gotten this to happen? Leave a 12-0 ND out of the CFP because OU/OSU/UGA/UM were stronger teams despite them being undefeated. If ND believed they'd be penalized by the committee for not being in a conference, they'd be in the ACC. But obviously that didn't happen.
So I see it as pretty simple. If the ACC could somehow convince ND, they steal WVU away from the B12, dropping the B12 to 9. Or if they think blood is in the water and want to expand and not wait on ND, steal WVU and add someone else.
Once that happens, the B12 is done. If the ACC gets ND, then the SEC and B1G will aim at Texas and Oklahoma, with Kansas/OkSU/KSU as possible second-tier choices. If the ACC doesn't get ND, I see the B1G actually getting ND at that point, probably pairing them with Kansas, while the SEC takes Texas and Oklahoma.