Not long ago, I hit an F6F with a 30mm ping right behind the cockpit, this, in R/L would most likely have killed the pilot if the plane had kept flying at all. The 30mm had a blast of a hand grenade. What happaned to the F6F was that he started leaking fuel, had to put one more 30mm, this time in his wing to knock him down. A b17 is fairly easy to kill with a single 30mm hit, aim for the fuselage fuel tank and hit with just 1x30mm and it will be put on fire.
What i think AH needs, although this sounds a bit like a dammage modell bug on some planes, is an improved dammage modell. Something like Il2's, in AH, we've had more or less the same dammage modell since the start, except for some touches on the GV's and such. It is still the "Hit the aileron with 1 or 2 20mm's and it will blow off" modell, existed allready some years before AH came, and although AH is more advanced then that I think it would do good with a "loose 15% of the wing sufrafce and get affacted". In AH, you can put 2 or 3 20mm in the left wing of a fighter, and as long as the wing doesn't lose an aileron or half the wing, the performance isn't affected at all. In R/L, the plane would lose quite much performance.