I'm doing an eight way battle on Rise of Nation Thrones and Patriots and I'm the Equestrian Empire. Unfortunately I have people instead of ponies cause people tend to be better at Earthly things since they have thumbs.
Can you create custom maps on that game? It's been too long. If you can, you should recreate that one very detailed map* and place all the empires in it then have them fight it out.
*someone find it for me, I can't remember where it was