Is it wrong that after two draws, the defending units remain in place (albeit broken, but still), and forwards - disappear (although not was completely destroyed).
I offer 3 versions:
1st (I do not like) is to remove both groups after draws;
2nd (in my opinion the best) is to restore health points and protection of both units and return them to duty as if the fight was not;
3rd (also good, but in my opinion not the best) - after a draw, to extend the time of the fight for a few minutes, so that it was possible to complete this fight is a victory or defeat, not a draw.