So what is wrong if it makes it good in AH (better than Yak-7 and P-39s), but did not make it good enough in real life?
The main reason is that we are not fighting like they did in real life. The only reason that planes like the Brewster, KI43 etc. can even get into combat with something like a P-51 or a 190D9 is because we fly cartoon planes as if they were cartoon planes. The 1940-41 hurricanes did not fly alongside an La-7 that caught a 190, forces it into a low alt turning fight and allowed the Hurricane to jump in with its 4 hispanos to finish the job. Or alternatively, some 109K4 pilot feels cocky enough to try and beat a Hurri2C in its own game - that will never happen if the 109K4 pilot was really risking his life. If he did, at the first sign of trouble he'll leave the Hurri in a hurry.
Less significant reasons include gunnery and spin/stalls. Gunnery was much more difficult in real life. 400 yards shots were considered long range. 800 yards shots on a fighter were virtually unheard of. Firing at high G was likely to get your guns jammed. Spins and deep stalls were feared. Very few pilots would attempt to hang on the prop, WEP engaged, firing at a plane 600 yards straight up until their speed drops to 0 and they fall tail-forward. AH backward-flying model seem to be quite forgiving (except a handful of planes) and most planes will simply drop the nose and continue flying without any control input (like reducing the throttle to less than max..).
Finally, no matter how hard you pull on your stick, YOU suffer 1G acceleration. Heck, I pull 6G without spilling the bear in my other hand. This gives a big advantage to planes whose only strength requires them to pull lots of G. Pulling 6G repeatedly with out a G suite is exhausting and if you do that while looking backwards you'll probably be looking at your butt for the next two weeks. I pulled 6+G with a G-suit - you are not incapacitated, but every little action becomes difficult and clumsy - like say, keeping your head straight... Pulling such a turn into a snap shot while still in high G was probably some feat that I doubt happened very often, unlike with the Hurri2C in a computer game. Unfortunately HTC decided not to apply G forces on us players.
4 hispanos on an obsolete plane did not do so well in real life. You need to be able to bring your guns into a firing position, otherwise their type and number does not matter.
