Undercity,org,Thunderbluff,and silvermoon are on the most northern side of the barrens.
Stormwind,ironforge,darnassus, and the exodar are on the most southern side of the barrens.
Everything in between them just went away, that include the crossroads, quilboar,quilboar, northwatch, all that stuff EXCEPT the great divide.
If both sides sent out their troops, who would win? This means forsaken,orc,tauren,and blood elf forces would be running out, same with humam,dwarf,night elf, and draenei.
There is a lot of stuff that could happen. Undercity can use plague bombs, ironforge can blow crap up, exodar can fly up and plant iteself on the other cities, I cannot figure out who would win.