There is a disparity between MG and cannon in AH that did not exist in WW2.
Just look at the top fighters in AH and ask why they are what they are. Is the F4U-1C three times as good as the F4U-1D? I don't think so. Is the quad 20MM as good in real life as is in AH?
There is simply a gap between the types that I cannot explain. The 20Mil was probably the best air of air weapon of the war but nowhere near what we see in here.
Don't you don't believe me just imagine what the F6F-5 would be in AH with 20mil and 50cal. It would OWN the MA in 1 tour.