Imho the Big12 isnt adding to add net positive value to the tv contract, like B1G is saying. They need to add so they have numbers for stability, and to have enough critical mass to have a leading voice during the next paradigm shift, ie when the superleague happens. If the Big12 is a large coherent group of the 2nd tier, then they will have the chance to shape the 2nd tier system.
Agreed, it's important for the Big 12 to kill the Pac-12 with its moves here and also to be in a position where the ACC leftovers, post B1G and SEC raid of that league, have no choice but to join the Big 12 (if we want them).
College sports is changing so fast; the Big 12 needs to seize its chance to lock in its status among the top 3 leagues when this long round ends. Just too bad the first 2 will be so far ahead.