They could fly at any altitude they like within reason. A shotgun on the other hand has an extreme accurate range of around 80 - 100 yards, and that’s if the target is moving slowly, and to compound things, there is no such thing as using a sight of any sort with a shotgun. The analogies are with baseball and tennis and not with any other shooting sport. As is the case with a bat or racquet, the gun becomes a part of your body and you watch the target, not the gun.
So we’re gonna need a home version of the Phalanx.
God help us if the radar locks on to somebody’s Piper Cub....