Thinking about it as someone with multiple 70s on who dual boxes, If I wanted to 5 box I could just create a DK on main accounts(2), transfer one of my 70s over to a new account and then create a DK(3), then do the same thing with another new account(4). By the time I get the 4 DKs to 70 I can transfer on main over to my other new account and I got a 5 box, and there are 3 accounts I didn't have to level to 55 at all... very tempting.