If it were a mater of the bullets peircing the windscreen then single engined fighters would have the same problem with pilot wounds, but they don't.
Not true.
I particularly enjoy tank hunting and I've tried all types of planes against tanks. The pintle guns always have a high chance of inflicting damage when I do a strafing pass - particularly with slow aircraft, from Hurricane2D to even the IL-2.
I just don't think that 7.92mm rounds should be that effective. If they were then I want to get all that useless armor off the airplane so it'll fly better.
This is sounding more and more like the old gunnery debate. Just like in those old debates, In terms of ballistics or physics there's no reason that a simple pintle machine gun cannot penetrate glass cockpits. Especially if the kinetic impact is amplified by an airplane speeding towards the bullet.
However, again, just like the old gunnery debates, there's more factors involved than just ballistics or physics. Like said, there's no on earth a tank commander would be stupid enough to leave the hatch wide open and enter a shooting contest against an aircraft.
The only reason we do that in AH, is the hand-held pintle guns are super super easy to aim with, and the pintle guns rarely get damaged by themselves.
IMO in concern with this particular issue with pilot damages when strafing vehicles, I'd say its the GV model that has to be changed, instead of the planes. I'm sure you'd hardly ever get pilot wound, if pintle guns were damaged or its gunner killed easily when an aircraft strafes it.