Many kills happened where the attacker was never seen.
In the cases where the attacker was seen, there were a lot where the defender didn't evade all that hard compared to what we are used to.
A lot of fighter pilots in WWII were not trained that much in ACM before being sent out into combat.
There were occasions of dogfights like we have in the MA, with the pilots pulling lots of maneuvers, using flaps, throttle control, and even (rarely) special accelerated-stall behavior of their aircraft. But those were not the majority of fights.
AH techniques and knowledge do translate to real airplanes. I went to Air Combat USA once and could easily see that in my mock fights against another Air Warrior pilot as compared to our fights against a commercial pilot (with much more time in real airplanes, but much less knowledge of ACM).