That's part of the secret dude! Think there's a real advantage when choosing the right units/combos... It would be aesthetically pleasing if you have the miniatures, but, if not we can always just use subs and our imaginations.

Edit: I just finished watching Ultim8te f8ghter .... bleh, what a bunch of meatheads. Seriously... There are a few intelligent ones, but I guess it taking one too many meat-fists to the head doesn't make the lightbulbs shine.