A bunch of posts further up I wrote how I’d fix WoW. Long story short, full reboot, go back to vanilla, reshuffle the factions. Horde (Orcs, Trolls, Tauren, Goblins), Alliance (Humans, Belves/Helves, Dwarves, Gnomes), and two neutral factions (Nelves and Forsaken). Add in a mercenary faction option for people to get out of being the Hero of the story by not being in the Horde or Alliance.
With that set-up, Horde is on Kalimdor, Alliance is on the Eastern Kingdoms, and the two would only intermingle when facing those global threats like the Scourge or Ahn’Qiraj.
Just to go on a bit further with the idea.
The Horde would have a story focused on building itself and establishing an identity for each race as well as the Horde as a whole. It’d emphasize a feeling of brotherhood and mutual respect. Thrall might be the Warchief, but he’d hold gatherings of Horde leaders every full moon or new moon or whatever makes symbolic sense, and all the leaders of the Horde would speak of the troubles facing their peoples, and offering one another assistance.
The Alliance would have a story rife with political intrigue and shadow wars. An example I gave was the idea of Garithos still being alive, having asserted himself into a position of authority over the living survivors of Lordaeron, and possibly having the Scarlet Crusade as his personal elite force, conducting brutal operations which, on the surface, support allies in the Alliance, while in reality, undermine the authority of other nations. An example was a riot in Stormwind which some noble manages to resolve peacefully, and the Scarlet Crusade comes in, slaughters all the unarmed rioters, and then hauls off the ringleaders of the riot for the Scarlet Inquisitors to question in the Stockades. He has people then move through Stormwind, singing the praises of the crusade ending the riot, making himself popular. He’d likewise support the Defias covertly, so that not only do Lordaeron refugees think twice about settling in Stormwind, but some Stormwind citizens think they might have a better life joining the Lordaeron Resistance.