Not sure I understand/agree with the consultants analysis that automatically expanding to 12 or 14 teams improves the Big12's ability to place a team in the 4 team playoff. IMO the only way the consultant's logic works is if the expansion teams have the ability to make the playoff. Adding a ND or BYU might improve our chances, while I can't see adding a UConn, Cincy or Memphis helping.
I think the Big12 adding a championship game and standing pat on expansion makes the most sense for now. If the Big10 or SEC poach the ACC, then it puts the Big12 in a position to add current ACC schools that are more attractive than UConn, Cincy or Memphis. My guess is the ACC schools that could come into play for the Big12 are Pitt, Loiusville, Miami, Va Tech, Clemson and maybe Syracuse.
The risk of standing pat is the Big12 being poached by the Pac12, Big10 or SEC. IMO the Pac12 might be the biggest threat. Since the Pac12 has fallen behind the Big12 in TV revenue, they need to make another play for Texas and Oklahoma as part of their realignment strategy. Texas and OU would also be attractive to the Big10 or SEC, but those confernces can find attractive targets from the ACC and ND for the Big10.
If the Big12 is going to be poached, adding Memphis, Cincy now isn't going to stabilize the conference as they aren't going to prevent UT or OU from leaving. If those teams would leave, the Big12 would have to be recreated at that time.