I know the fantasy here is that the Big 10 poaches Oregon, USC, Washington and one of Stanford/UCLA/Cal, which leads to the PAC12 falling apart and Utah/Colorado/Arizona/Arizona St defecting to the Big12. And I guess Wazzu, Oregon St and 2 of Stanford/UCLA/Cal join the MWC?

Which sounds great for the Big 12 on the surface, but if that happens it's a prelude to a breakaway by the Big 10 and the SEC. Either a hard break (like the FBS/FCS split) or a softer break (like the P5/G5 split), but in either case it would cement the Big 12 as not competing at the highest level.

Truthfully, that's why I don't think it happens. The B1G doesn't want to compete directly with the SEC, they'd rather be the leader of an alliance competing with them.