AA guns are made more resilient from bombs and rockets according to the previous patch notes.What I noticed in that regard is that the 5 or 6 men of an M5 AT gun will in >90% of cases die from a single FW 190 G3 (the fast one with 4x 50kg bombs), while bombing a Bofors with 6 men killed only two men or so. Is that a special stone-paper-scissors resistance bonus for AA guns vs airplanes or was I just incredibly unlucky that one time? I think it was in a forest, maybe that's why.
As they should be the ones countering planes, not the other way round.