Something that’s quite different between Elder Scrolls Online and World of Warcraft is the lack of exclusivity of the factions and races that make up those factions in the former game. In World of Warcraft you wouldn’t ever expect to see a Troll character with the Alliance or a Draenei with the Horde. Yet in Tamriel I have often seen races I wouldn’t expect to see as I level through the Ebonheart Pact zones.
In many MMORPGs, World of Warcraft being only one example, your choice of races at character creation are bound to your faction choice. It may be possible to break out of that by paying real money to race-change or faction-change your character, but generally it’s a hard and fast association in any case.
There are cross faction NPC races usually, groups that you will do quests for regardless of where your character’s loyalty lies. There may even be cross-faction in-game structures like the recent WoW expansions Class Halls, but they’re a very recent addition to the game and are it seems a one-off too.
Elder Scrolls Online had loose faction-racial links as a background feature of the MMO incarnation of this world. The three factions in ESO each have three races primarily associated with them. Characters from those same races can be found anywhere in the world, however, a Khajit settlement in Shadowfen is perfectly plausible it seems.
There are other examples too, a Bosmer scout working for Nord villagers for instance. The factions may consist of specific racial/political groups, but unlike in other MMORPGs members of those same, mostly faction-affiliated, races are also found in rebel or independent groups elsewhere – “behind enemy lines”.
Certainly in WoW there are no humans operating freely in Horde territory, nor orcs walking around Stormwind. It can be argued that both sides have elves, but there’s a world of difference and millennia of separate cultural evolution between Blood Elves and Night Elves as just one example. The factions in Azeroth are, perhaps, a little too dominant in their control of territory. Yes, you find the other faction’s races as opponents, but what about as quest givers, merchants or potential allies?
I like the looser relationship between race and faction found in ESO. It’s surprising to see an ‘enemy’ NPC in a town of your own faction, but adds a wealth of possible story ideas and complications with a more nuanced view of the political forces shaping the fantasy world.