I would guess Yormark has a priority list for both PAC now and ACC future (leftovers in ACC case) and a pretty good idea of who he wants based on going to 16, 20, or 24 total teams.
For example, if he never wants more than 16, he prob would just take 2 PACs, and wait on 2 ACCs. But if he wants 20, then 4 of each. For 24, you need 12 more total, and I don't know if the "last 4 in" would be worth it - you're talking Cal, BC, GT types.
Predicting the future for the 100th time... 4 from the PAC (prob the M4 because B1G will somehow take UW/UO) and 4 from the ACC. 20 teams total from east coast to the desert southwest.