The ACC could opt to keep the current 2 divisions and require both divisions to play a round robin division schedule plus whatever cross-division games. Here is the kicker: the ACC could decide that the 2 highest ranked teams, regardless of division, would be selected to play in the CCG. In theory the CCG could involve 2 teams from the same division some years.

The benefit is that if 1 division has 2 teams ranked ahead of the "champion" of the other division, then the highest ranked team (assuming it wins the game) benefits from beating a higher ranked opponent. If the highest ranked team was not in the Top 4 going into the game, then it could be enough to push that team into the Top 4. If the lower ranked team (2nd ranking among the 3 teams) pulls the upset, then the ACC may be able to get 2 teams into the Playoffs (depending on how the other games play out). It is unlikely that the lower team would have a chance to move up without playing the CCG. It is even possible that lower ranked teams, who ended up playing in a CCG, could leapfrog them in the final regular season poll.