The AA50 game we just finished the US bombed the hell out of Germany. We used the unit counter chips (red-5, gray-1) to show damage. It worded ok. Even if there is a mix-up and chips go flying (which happened) you tend to remember how many damage there was. What seems to get mixed up is how many tanks vs inf you had. Even if you had different colors to show damage (good idea), you might need two damage colors to show increments, other wise you could have towers in some cases. For at least 2-3 rounds Germany was damaged into double digits.