It's not just the markings, it's training for the crew since being a gunship vs being unarmed is different, different equipment inside for the litter vs door gu

It's not just the markings, it's training for the crew since being a gunship vs being unarmed is different, different equipment inside for the litter vs door guns, less medical equipment because you need to have ammo, different crew since a gunner isn't a medic, etc