Nerf the single largest source of the imbalance, and the reason all the fotm trash faction swapped to begin with for a start: emfh racial. Once it’s down at the level of every other racial instead of dramatically overpowered, we can begin.
That’s step 1.
After that, the sad reality is, people aren’t going to swap back horde unless they’re forced to, by making alliance outright worse instead of just balanced. I think we can agree there that would be terrible balance wise, so we need another solution. The easiest and most obvious is to simply make all instanced pvp cross faction. Congrats it no longer matters if the entire arena ladder is exploiting one race/faction combo, because they’re going to get split across both sides unless running premades.
Which brings us to step 3…open up the group finder to pvp, and make it cross faction. Now everyone can get premades easily.
Step 4, now we limit the number of premades per team to 1x 5 man per side, for a 10-15 man bg and up to 3x 5 mans per side , for 40man bgs.
Casual pvp is almost entirely fixed. You can still play with friends/find groups regardless of faction, there’s no dramatic talent disparity between the two factions, and there’s going to be more fair games generally speaking by limiting how many premades can be on the other team. Very good pugs can beat a 5 man, they stand almost no chance against all but the most inept of full premades.
Last but not least, rbgs is a dead bracket… Convert it to solo queu rated. Plenty of players would play the hell out of it.