I've seen all these Siege of Orgrimmar threads about why doesn't Dalaran and Kirin Tor just teleport the city to Orgrimmar and beam mages in. But... how exactly does the city float? Is there like a group of mages who constantly switch out because of how tired they would get. If this is the case, then if they teleported the city from Northrend to Orgrimmar... Everyone would be tired and the Horde could easily knock the city out of orbit.
Does anyone know what keeps the city aloft?