[Fictional story]
In the 1990s, the anti-aircraft tanks used by the Yeager Army became outdated, as were too slow, and the tiny targeting angle with the extremely long lock time of the missiles made them too vulnerable to protect airports and important locations. To fix this issue, a modernized version was introduced. The key difference was the total absence of the missiles, and instead, two coaxial 20mm guns were installed on the improved, automatically aiming turret that would target aircraft in a 6-mile radius. Air-to-ground missiles were not a threat, as flare dispensers have also been put. The engine's performance was increased, so the tank was quite a bit faster than before.

Important note: this is not my build, all I added were better guns, engine, flares and autoaiming rotators. To the Android folks: the mod was only used for sounds and looks. The 20mm cannon mod is fully Android-compatible. If you wish, you can just put regular wing guns instead.