If you're going to have Army and Navy, might as well take Air Force as well, and another Eastern team to balance.
Alternatively, if I'm ESPN maybe I try to satisfy the unhappiness of the bigger ACC schools and the mistakes in past realignment, by taking a page out of the plan to dissolve the Mountain West or American in order to free up teams from contracts for a re-arrangement with the Pac.
Let's say it takes 12 of 15 schools to dissolve the ACC. The 12 most valuable schools dissolve the ACC and recreate it, dropping the three weakest (BC, Cuse and Louisville?), adding Stanford, Cal, and UConn. ESPN provides new financial terms that are more acceptable to FSU, Clemson, UNC, and don't leave anyone else worse off. You may get a more stable conference with an uptick in revenue.