DO M3 cargo loads have equal game effects as the C-47? Seems like a M-3 cargo load should only be 1/4 of what the C-47 can haul...
But that would probably just mean even more M3s.
I think they should make those Opel cargo trucks in the hangar drivable, and have them be the cargo haulers (at a lower speed over rough terrain). Give them a formation option - like bombers; you get a couple of drone trucks that will follow your truck around and drop supplies when you drop. Maybe perk them with a small value too.