Game was designed for 1 client per player, or switching between windows.
Playing with 30 characters at once is not as it was intended and its not possible without additional left-side programms
The very reason why it is "legal" - money outcome.
Blizzard closes eyes on it since multiboxing kids bring moneys, but Warmane mindlessly copycating that rule even tho on Warmane multiboxers bring cash once per years. However, not each multiboxer donates.