>>713031207
That's something else the WoW writers constantly ignore, casualties, attrition, and scale. According to the original numbers given in the Warcraft RPG the Alliance had way, way more numbers and land than the Horde, which made sense since the Horde were supposed to be the valiant underdogs in the original vision. But then the writers forgot about that and all sense of scale was lost, plus because of how the game works there can be no consequences narratively, so you get stuff like the Alliance conquering Orgrimmar and then just tipping their hat, waving their hand and walking off like nothing happened.

And it's only gotten worse since then, I think the Scarlet Crusade has been reused as an antagonist faction about 5-6 times now, apparently they have infinite men and resources since they not only always come back, but they come back with more people and more power than they ever had before, even though they just lost thousands of guys in their last big campaign.

TL;DR
Blizzards staff cannot write.