The first solution that comes to mind, though potential inelegant in practice, is to disallow opposing the same army more than once, just as you cannot play the same army more than once. To ensure this happens, you would pair up opponents and assign maps before drawing armies (which I thought should be the proper order anyway) and then as each player draws their army, their opponent makes shore the army drawn is one they have not faced previously, forcing a re-draw if they have. Might cause multiple re-draws in later rounds, but it'd prevent players from shooting themselves in the foot by making them play against their own army multiple times.
Thanks tshill. You're definitely going to be attending by the way, right?
