I haven't played seriously since ~2017 or 2018, but I would like to comment that I believe one of the simplest solutions is having the toxic rivalries come to an agreement/halt. (Like do you guys really care about a clans video game appearance/reputation as adults most likely over the ages of 25 at this point?) It comes down to the facts of having a game to play, or playing it miserably.
When I was younger pures were designed to beat the shit out of mains and gang up on them. I really would have loved to see when FO got targeted by ROT that the entire community would have joint together and just fought ROT back. Yeah we would probably lose but, the insane amount of action that brings and the ability to tell one of the most dominant main clans to fuck off would have been awesome.