Orcs- Thrall ( Current status: Depowered)
Troll- Voljin (Current status: dead)
Tauren- Carine (Current status: dead)
Undead- Sylvanas (current status: hit by villain bat)
So the alliance.
Human- Anduin (current status: Alive, most powerful light user on Azeroth)
Dwarves- Magni ( current status: alive, a demigod for the planet and personally has threatened the Horde specifically even though the alliance was also using azerite)
Night elves- Tyrande ( current status: alive and a demigod to possibly one of warcraft actual dieties)
Gnome- mekkatorque ( current status: alive and now king of all gnomes)
So basically Horde leaders get killed or weakened while alliance leaders never die and become demigods.
This is why Rezan was killed too weaken Talanji because all Hordeleaders need to be weak.
This just in! Leaders of a society that revolves around senseless violence have a lower life expectancy than leaders of a society about protecting yourself and leaving everyone else alone.
A society that protects itself and leaves everyone else alone doesn’t form an alliance, it isolates. Quel’thalas fits your description, altho their isolation led to them being slaughtered by Arthas.
It does when the planet it’s on regularly faces extinction level threats, and one of the other global super powers is a society that revolves around senseless violence.