Asking whether the Big 12 can do anything correctly isn't a bad question at this point. During realignment the conference very nearly dissolved into adjunct wings of the Big Ten, SEC, and Pac-48 (or whatever that was going to be.) The TV deal seemed okay until Texas bought eight middle fingers off fresh corpses, had them sewn onto their hands, and then raised all of them in the direction of the rest of the conference by starting the Longhorn Network. The first year of the playoff saw the Big 12 lose out in part due to their inability to stage a conference championship game.
It's a family, sure, but it's the one on your block whose house could go empty at any minute without anyone raising an eyebrow. Oklahoma President David Boren said the conference should "strive for a 12 team league," meaning in theory something like another round of banditry could shake loose two other teams from somewhere else. (Everyone also still hates the Longhorn Network, but that's not news anywhere.)
That somewhere else is a real mystery, but if we're into wild speculation, let's at least make it semi-plausible wild speculation.
Take the Arizona schools. Both are Pac-12 schools without century-deep roots in the conference. Both joined the Pac-10 out of the WAC, the conference formed in part to give the Arizona schools somewhere to compete. Both are current Pac-12 members, meaning they're probably pissed off at Larry Scott, whose global visioneering and quirky conference TV strategy ended up putting the Pac-12 on a profitable but less visible footing than other conferences. Both are tied together institutionally, and couldn't really make a move without the other. They're a package deal, and a tidy one to get to 12 and also check a lot of other boxes at the same time on the Expansion Partner Checklist.
Or alternately, there's the Jones 'n Jesus option: taking back old SWC member Arkansas, and then grabbing Liberty, an upcoming program with tons of cash and a foothold on the East Coast. This makes no sense whatsoever in a lot of ways, but we wanted to type "Jones 'n Jesus." Arkansas would only leave the SEC if they were insane, but they are insane, so you always have to consider this a real possibility when dealing with the Razorbacks. Disregard this in any format besides absurdist comedy, or reality. Same thing.
Finally, there's this: you could just add a random school and Memphis, because Fred Smith would probably give you free FedEx delivery for life. If this seems farfetched, ask yourself: would Steve Patterson see this as yet another opportunity to cut costs at Texas, and also send the Longhorns' non-revenue sports teams to road games in giant shipping envelopes? It's sounding more probably now, isn't it? We thought it would.
(That random school? Probably a Christian online academy set up by Houston Nutt specifically to get him back in the coaching game, which is another one of those jokes we don't want you to take seriously until it actually happens.)