How would that any different from pilots in armoured seats still getting killed from 6 oc attacks due to penetration? Remember that most of the fuselage is hollow one way or another.
The P-38 fans whine about everything

remember? They whined about it being porked in early AH1, they whined about glass tails in later versions, they whined about the flaps too.
Joke aside, not a single person who complained about the P-38 ever brought up any evidence regarding to their claims.
There are a lot of factors in work here - one especially, which people don't seem to think much about, is that the hit detection has changed with AH2, and a lot of people are shrugging hits off which in AH1 they'd have died from, due to pilots death or plane explosion. As a result in AH2, a lot of more lead fly through the air, and especially if a HMG armed plane is chasing down a P-38, it has to shoot more than it used to.
In AH1, they'd have simply died. In AH2, they are surviving, albeit with a pilot wound.
As for the F6F, there are so many variables intertwined that its hard to tell what you're seeing to what just you describe. I'm pretty aggressive in trying to push my team mates into fields and actively suppressing it when flying CV ops, so I got a lot of damage in F6Fs over the years. Gun breaks, pilot wounds, oil bursts, gear busts, rear section falling off, etc etc.
If you are constantly getting a certain type of damage, then it has a lot to do with you being constantly in the same conditions as the last time you got that damage. For instance, in my experience the type of damage you get is pretty common when I'm strafing an ack. It takes a lot of HMG rounds now to get precise hits on ack, and you are longer exposed to ack fire than you were in AH1. Add in the fact that the AI ack fire algorithm has a certain set method of 'aiming' at your plane, and it's really no wonder why gun damages in a certain section happen repeatedly. The chances are, when you are moving towards ack, the ack always 'aims' for a certain spot.