AP rounds were not anti-tank rounds. Common beltings had AP rounds so that the rounds punched through pilot armor to kill the pilot.
It has nothing to do with scoring, nothing to do with mission role. They simply were mixed for best results.
Allowing the changing of belting allows for gaming the game. In TargetWare you had this option and all you saw were pilots customizing 100% of the strongest most powerful HE round, removing all weaker rounds.
It was not realistic in any way.
EDIT: I also meant to include: This is already taken into consideration. Hispano rounds, for example, have armor piercing capabilities as well as HE capabilities. They are not all AP, not all tracer, nto all HE.
The problem is already taken care of. HTC models the ammo as "averaged" penetration and "averaged" HE based on the standard beltings. Individual rounds in real life may have been weaker or stronger but in AH they average over the 5-round (or 10-round, or whatever) belting pattern and apply that average to all rounds equally for in-game purposes.
