How about we not join forces? Instead, we leave each other alone until they infringe on our claimed territories.
Crud. Uh... I'll claim North America (including Iceland), I guess, before anyone else snaps that up. Mua ha ha ha ha!
Yeah, that sounds like a good idea. We don't need to join forces, just not fights and subdivide the world, therefore forcing the heroes to combat us on multiple fronts.
Sorry, but you can't claim all of north america, because, for one my evil base is sitting off the coast of Florida, and I have a henchmen recruitment station in New Jersey(kind of need this for henchmen replacement). I'm not interested in world domination, I just want to destroy somethings and/or states.