If you were writing the specification for a new AH3 map, what single characteristic would guide you in the map design.
Wanted: Anything that separates the place to fight at and the spawn. Both attacker and defener should have to / have a chance to move some part. Also, some (not complete) separation of air and ground fights. GVs fighting over a town with aircraft needing 2 minutes to up and drop bombs is no fun for the drivers. Aircraft fighting over a town, only to see the capture or resupply happen by a stealty m3 is no fun for the pilots.
Don't care: How it looks. It could be textureless gray terrain without any clouds.
Calderas picture looks like a good start, but this layout only works for 2 fields. Moving the towns perpendicular to the side of a row of fields would at least allow an infite long row (or a loop) of fields. GV spawns for such setup: Zero. Allow for some air-only fights. Defenders might be further away than usual, but in the end the final thing to defend against is goons.
GV-spawns placed where ground fights can happen. But not on opposite sides of a town, where a fight happens after significant damange has been done. Instead, some terrain features is needed: The town being placed in a valley or on a mountain with access from only one side. The spawns are placed on the same side of town, but opposite sides of the area allowing easy access. The side that achieves superiority in that area can move in to capture/hold. Discourage too much air support by vertical and/or horizontal separation from the air field.
Where not enough towns are available (each field can only have one), vbases could work as proxies. Located in the middle of air bases, creating an area to fight over. Now to add some strategic value, a spawn from such vbase right into the center of a town would basically guarantee that the side that maintains control over the vbase also owns the airfield.
Coasts and carriers. Instead of airfields right at the shore allowing to launch close enough to shoot before the gear is up and doors closed, vbases right at the shore. Not too far back, few miles maximum, backed up by an airfield. As a combination of the above, the field offers a place to fight at (without being the spawn), and to avoid that attackers from the sea are drivin back into the ocean, the vbase might come with a spawn right into the airfields town. You manage to get a foothold, you get both fields.
Possibly, a similar feature as for low accessibility towns could be created for carriers to create some ship-ship fights. A fjord with a field of some value placed in the back, would force ships to battle it out at sea. The winner can move in to attack the hard to defend but valuable field.
Strat targets with ground access could use the layout with GV spawns as described above. Resupplying wouldn't be from the opposite side (75mm shells from one side, care packages from the other), but require to fight for access to get supplies through.