You can spawn a drone without brain, or let's say his virtual AI "crew" by holding Alt or having Place vehicle with crew unchecked. This cannot be changed afterwards unless you delete that vehicle and replace it with completely new that has that virtual crew. Is it intended - if so shouldn't we have ability to spawn that AI and add it inside that vehicle?
U could say it's useless to solve but if you let Place vehicles with crew unchecked to spawn some empty vehicles and then spawn UAV it has literally no brain.