Since people seem to be gunning for air as a ground unit type I'm left wondering what would be their specialty vs the other vehicle types besides interaction with AA? Attacks rear-echelon and support formations unless providing support for a frontline unit? What about targeting rules when there is enemy air involved? What about unit capabilities for these air units? I don't think "jungle fighters" works in this context, as funny as the pun may be.
It's surely some programming work for Steve, but I think you mostly move the existing GSF rules and mechanics into an aircraft GU class as far as targeting rules, probably modifying a bit so that AA in a targeted formation does an appreciable amount of mitigation and counter-attack. I think an aircraft class should have a fairly large size (aircraft may only be ~10 tons, but we have to account for the amount of maintenance and support crew+equipment to be shipped around with them) and limited armor options, probably similar weapons choices to LVH as well. Targeting enemy air would probably work similar to how counter-battery fire currently does. As far as unit capabilities, same rules as apply to other non-INF types should work well enough.
IMHO, the biggest job will be on balancing rather than create ad-hoc rules, and, of course, some works is required.
As Nuclear said, all ingredients are there, including evasion which could be a factor against AA? Fighters could have more and Bombers less?
Regarding the "Jungle fighter" you could imagine being either the loadout or the structural plane changes required to be effective. For instance the "jungle fighter" uses napalm while the high or low gravity will suffer or gain evasion.
Eventually, air ground units won't get any fortification.
