Starting in 2020, it looks like the ACC has simplified the bowl process, at least from the fan perspective. Basically, there is no pecking order, hierarchy, or tiers.
After the New Year's Six picks the conference champ and any other at-large teams, the following bowls (listed in alphabetical order) will work together with the ACC to determine bids:
Belk Bowl vs. SEC (odd years) or Big Ten (even years)
Camping World Bowl vs. Big 12
Gator Bowl vs. SEC
Holiday Bowl vs. Pac-12
Military Bowl vs. American
Outback Bowl (only if the Big Ten is in the Orange Bowl) vs. SEC
Pinstripe Bowl vs. Big Ten
Sun Bowl vs. Pac-12
untitled Bowl game at Fenway Park vs. American
Finally, if there are any ACC bowl eligible teams left after that, one of the three bowls below (listed in alphabetical order) will get an ACC team:
Birmingham Bowl vs. SEC
First Responder Bowl vs. Group of 5
Gasparilla Bowl vs. SEC
This makes it a lot harder to predict which bowl any given team is going to, which will probably seriously cut out a lot of message board discussion. I think the safest bet is that you won't see a team in the same bowl in back to back seasons. This also looks like the "one-win" rule won't matter, or any rule about where the ACCCG loser might play.