To add onto what JG said, if you're going to do that, then I'd probably suggest doing it with Humans in Elwynn Forest (outside of Northshire Abbey) since that zone can easily eat up a lot of hardware. You also have quick access to a main city (Stormwind) if you're on a high populated server, although more people are probably sitting in the Ashran hubs compared to any of the other major cities at the moment.