Ok, maybe different ammunition types isn't practical, but please don't let a repeat of Warbirds 2.6 happen to AH.
Just to recap, in 2.6 the MG 151 was given a flat nosed "Geschloss" type mine shell which was used historically against bombers. Problem was, it was useless against fighters, and AP 20mm ammo was still better against bombers than the Geschloss type, which makes no sense at all. In DoA you have regular ammo and incindiary, and it has different effects on different targets, something like that would be perfect for AH.