Tbh I LOVE the legacy rivalry idea, ravens titans rivalry renewed.
but I see what you’re saying, like nothing else really does make sense in all honesty
would probably have to be an NFC opponent - more likely in this hypothetical scenario it would be Washington or something like that that's more geographically based
wouldnt necessarily be legacy based for everyone
but you can have in some cases a yearly battle for supremacy in a region - the Texas game, the LA game, the Pennsylvania game, the Bay Area (formerly i suppose) game, the New York game
it doesnt fit perfectly and im sure in this scenario the NFL would probably rather Steelers Cowboys every year than Steelers Eagles and Texans Cowboys...
likewise NFL would probably want Giants Patriots in stead of Giants Jets and Pats vs ???
logistically its clearly pretty difficult and for the most part in the scenario they've come up with these rivalries still have a chance to happen anyway