UNC for one, they even scheduled two OOC games with Wake when the ACC schedule dropped them off their play list. UNC is more important for NC State than the other way around. Duke tops UNC then Wake and Virginia.

But this is all inside the beltway stuff. Divisionless football means schools will pick their protected games. They will probably do something similar to what other conferences have done, having each list their preferred opponents in order. When two schools match as top opponents they are locked off. This will determine who each winds up as a rival with. That is the sensible way to do it. If a couple schools are left over.

Note the Math does not work for 3 rivals with 15 schools. You have to either go down to 2 or up to 4. At 3 you get 45 (3 opponents for 15 schools), which means 22 games and one school left out. Logically if you did that it would be ND, who would probably have Pitt and BC as the only rivals.