What about Open Beta before launch? In form of Event (for example Christmas). Santa was kidnapped by Evil Robots and is kept on Cradle planet, Kelsey. Players Have to win few battles to get him back. How to get units? Players can win tokens (for serials, for Christmas Festive Items, etc), which can be exchanged for Event Units. Which could be used like Genesis ones (whatever it means), but will disappear after Event.
That could works like large scale testing, and would help you with balancing forces, I suppose
Each battle can be in different conditions, so many tweaks would be applied between battles 
