From my experience in game trying to aim, if your aim is off, you just miss everything with a laser stream of bullets all going to the wrong place because you're bad. And if anything, IRL gunners should have had less experience with their tools shooting actual planes than we have with our in game tools in an in game context.

So especially for guns like the M16 truck or wirbelwind with multiple barrels and high rate of fire, wouldn't it make sense to intentionally set them up to be a spread out rectangular long field of fire to fudge the lead? Maybe even the barrels are designed to rotate around in a bracket from recoil or wobble, etc. on purpose to add noise?