[DRG]

In SP, guns are not the target, the crew is and that is baked into the basic code and we don't see the need, or have the desire to change that. Once abandoned guns cease to function and are no longer "targets" for the AI or the human player but a crew that has been forced to retreat from the gun can rally and recrew it which re-activates the gun to target status but until they recrew the gun THEY are the legitimate targets.

Vehicles are targets until destroyed and then maybe a crew bails out and then the surviving crew becomes a legitimate target but a gun crew is not inside a gun, it crews from outside and that's the way it is.