Think the reason it's not available as an attack plane is because it ups with drones. While this isn't a problem while using it as a fighter, drones will just crash, it could be used to build up lots of fighter perks while bombing objects(i think when attack is selected all perks are fighter). I've only been here a little while so i may be wrong about this stuff but I completly agree that A20 should be available with a zero ord loadout with an attack selection but drones should be unavailble when this option is selected.