An interesting idea, but the diversity is what makes this game interesting. In truth, each of these weapon systems (pardon the modern term) was the result of a large number of design choices from engine, to airframe, to guns, to landing gear, to external stores, and on and on. IMHO, moving toward "generic" weapons is a move in the wrong direction.
I'd like to see more realism. Let us pick the ammo type. Let us pick the order of the rounds in the belt (3 AP, 1 HE, 1 tracer, and the last 10 rounds tracer, please). Let the guns that jammed under G-load have a chance of jamming under load. Let the barrels warp if you hold the trigger down too long.
I don't want to return to the days of sims that treated Zeros and Spitfires the same except for the paint job.