Originally Posted by
Jokubas
The factions aren't like this because it's an MMO, they're like this because they decided on enforcing two factions as part of the game mechanics. The Alliance and Horde would be able to be much more fluid if we weren't assumed to be their most loyal servants, which is something other MMOs have let happen.
Right after Warcraft III, the factions would look something like this:
Sentinels: Night elves
Horde: Orcs, jungle trolls, tauren, ogres
Western Alliance: Lordaeron refugees (Humans, dwarves, and high elves in Theramore)
Eastern Alliance: Stormwind humans, Ironforge dwarves, gnomes
Illidari: Naga, blood elves, and draenei (on Outland)
Forsaken: Undead remnants (in Lordaeron and the surrounding areas)
Over time, those alliances would shift a bit if we assume similar threats (while keeping the original concepts).
When the Eastern Alliance finds out what happened during the Third War, they'd probably reestablish contact with the Western Alliance. Most people would probably leave Theramore for the more stable lands in the east, merging the two Alliances while leaving Theramore as little more than an outpost. The Horde, a handful of refugees themselves at this point, would probably keep mostly to themselves and simply try to solidify their holdings. The night elven Sentinels, shown to be a powerful force in Warcraft III, would probably remain xenophobic at first, but entertain diplomacy with the people who saved the world at Hyjal. Leaving us with essentially the same list I made before with the difference being a single Alliance.
Really, there's no reason for any of these groups to form permanent alliances or harass each other, especially considering the more important threats that lingered or would be coming. Nations can ally without having to literally join together.
If I did have them act more desperately and join more fully together, this is how I think it would go down:
With their natural allies returning to their realms while new threats begin to harass their borders, the night elf Sentinels contact their old friends, the tauren, and decide to ally with the Horde. By the time the Battle of Mount Hyjal happened, they realized that Grom's killing of Cenarius was not the norm, and they otherwise have a lot in common with this shamanistic Horde. It's a shaky alliance at first, but they all very much care about the world they live on.
Meanwhile, with the Scourge being an ever-present threat and the Lordaeron refugees now backed by several strong kingdoms, they decide to retake their homeland. When they arrive, they find the Forsaken. After initial skirmishes, they realize that these people are not under the sway of the Scourge. Many are wary, but the reunion with family and friends they thought dead is powerful. The Forsaken join the Alliance and together they rebuild Lordaeron as a shining beacon of the tenacity of the human spirit.
For the most part, I think these factions could have stayed solid throughout the expansions.
Horde: Orcs, jungle trolls, tauren, ogres, night elves
Alliance: Humans, high elves, dwarves, gnomes, undead
Illidari: Naga, blood elves, and draenei (on Outland)
When Burning Crusade happens, blood elves and draenei are already accounted for. This expansion would happen entirely differently. The Illidari races would open up as playable (no factions in gameplay, but it would still be the best time to add them). Instead of being about taking down an inexplicably insane Illidan and his traitorous "allies", because those are playable races, it would be about stopping the Burning Legion's Burning Crusade.
When Wrath of the Lich King happens, living Nerubian remnants would join the Illidari, who have now come back to Azeroth as a respected nation. When the Cataclysm happens, the Bilgewater Cartel would still join the Horde, and the Worgen would still join the Alliance. The Forsaken wouldn't attack them this time, but the Greymane Wall would still break, opening them back up to their old friends. In Mists of Pandaria, the Pandaren wouldn't need to join anyone. If they did choose an ally, I'd pick the Horde. Not because Chen helped with the founding of Orgrimmar, but because they were once friends with the likes of the tauren and night elves, who are both Horde in this version.
If Warlords of Draenor happens this time, it wouldn't be because Garrosh led the Horde to ruin before being captured. The addition of the night elves would have insured that if Garrosh gained power, a civil war would have started much earlier. At this point, Garrosh would either have been ousted, or the Horde would have fully split.
"True" Horde: Orcs, trolls, ogres
Nature Horde: Night elves, tauren, pandaren
This would cause some complications, however. Thrall would definitely see that "Nature Horde" as much more what he wanted his people to be, so to be completely realistic some of the races would be scattered across both. In fact, characters like Maiev might even side with Garrosh's Horde if he saw purity and destroying night elven lands as less important considering other factors.
Well, I could probably go on forever with this, so I'll stop for now. I'd love to talk about this from other perspectives as well. I ignored Onyxia for the most part here. It's possible she could have turned the Eastern Alliance into manipulated antagonists until she was ousted, leading the Western Alliance to instead ally with the Horde as the Warcraft III hero faction. If I took our known history at face value until certain points, different things could have happened. Sylvanas probably would have taken credit for the Wrathgate attack and been kicked from the Horde had the factions not been enforced, and the blood elves certainly would have completed their talks with Varian in Mists of Pandaria.