Dalaran is neutral, i think Stormgarde was nearly wiped out so it barely has any people? and Alterac was completely destroyed because they sided with the horde in WC2
Stromgarde always had enough people for the Forsaken to kill during their questing experience.
The kingdom of Alterac was destroyed but it’s people survived and became the Syndicate. They are still around to this day doing all sorts of Roguish criminal activities. They even show up on BfA’s version of the Arathi Warfront.
“The undead being who stood before the king of Stormwind was shorter than average but otherwise unrecognizable. The beard was gone. Cut? Rotted away? And the hair was dark with dried blood and ichor. He smelled like old vellum: dusty but not unpleasant . Faol had died when Anduin was a child, and the boy had never gotten to meet him.”
-Before the Storm
Strom is at best a satellite kingdom whose line of kings is fractured, and whose capital city is under constant and perpetual siege in the Arathi warfront.
Dalaran is a city founded by Arathi magi, so in essence an off-shoot of Strom and thus the same line.
Alterac was ruined in the Second War, and ultimately left to the annals of history after Lordaeron and Stromgarde overthrew Perenolde. There is no kingdom of Alterac anymore, and what’s left of its people form the criminal organization The Syndicate.
So you get a choice of fractured human line, mages of the fractured human line, or a kingdom of thieves.