Hmmm AA guns as casualties……
Now we have ground based soak off hits to take into consideration. They shoot their load against the planes and then can be taken as casualties without losing any defensive pips to the defender.
One change this will bring is that it makes strafing attacks into AA fire more likely. Now, as the defender, you have to consider your OOL and if you really do want to lose a 0 defense AA gun or keep it in case your opponent retreats. I know I strafe every opportunity I get and it would be sweet if my opponent chooses to lose his aa gun when I was going to retreat anyways.