COIN Aircraft?

[Mobhack]

The AI picks from the normal fighters class, and the units in there are mainly armed for armour-heavy combat. The types of battles that are SPMBT bread and butter.

The main thing the second fighter class is used for now is as a useful dumping ground for rare beasties that are OK in human hands, but aren't wanted as part of the AI strike plane pick. Also, more anti-infantry load-outs of the same sort of stuff you see as strike planes in the usual class 44 can appear here.

And as the description of the unit class in the Game Guide says - the class is a little more open to targeting infantry units presented to them than the normal more vehicle-oriented strike plane class. (You would have to probably run a lot of test scenarios with both in the target area to actually notice that much of a difference, though.)

So - a humans-only and rarities dumping ground for things like the tsetse Mosquito with a 6 pounder, or armed trainers etc.