In some way, RL kills are way more often 'lucky kills" than in here. The combat environment is totally different in AH, our view easily being somewhat distorted my the huge amount of kills made, both absolutely as well as per time/sortie.
Also, a slow rifle caliber plane in AH doesn't only face the challenge to kill it's opponents - one main reason it's less effective is that it competes with cannon armed friendlies for that kill. Before you can saddle up and kill the enemy, another player on the same team would have. You simply get your 12 cleared way too often

It would be totally different in a scenario / fso setup, in which for example Ki-43 would face Wildcats or early Hurricanes / Spitfires.
Once you saddle up, .303's and comparable guns can be deadly. Hurricane I will shred any plane at D200 if you get a proper gun solution (I have almost 800 kills in LW arena in it, including B-17s), and even a D3A with only 2 MG will kill (I have shot down Il-2's with it).