I might try to add functional flares to the UH-1 and Hind. The pilot would get warned of incoming homing missiles. Once deployed the flares would either just disable the homing mechanism or change the missiles flight path.
Speaking of homing missiles: The light anti-air turret is already quite the threat for pilots. Once done the heavy version will give them an even harder time attacking. The Stinger and Humvee Avenger shouldn't be that much of a nightmare anymore because I will nerf them. But there's already a new idea that might shorten pilots lifespans soon. A radar that detects hostile aircraft which will then be shot down by huge homing missiles. It would be fully automatic, including a couple of downsides. The radar wouldn't be able to detect aircraft that is not in direct line of sight and the missile launchers could only shoot one missile every couple of seconds. Would be neat to have a radar that detects enemy planes and tells e.g. three launchers to shoot down three planes simultaneously.
Nearly forgot to mention that the very next thing I'm going to do (After the Hind) is to add some sort of detection for homing missiles that distinguishes between air and ground targets so they can only be used against the stuff they're made for.