“Before we undock and begin to prospect, we need to NPC the vehicles. To perform this act you need to already be in a mining vehicle (SX-65 Groundhog or FK-7 Airspeeder). To NPC the other 11 vehicles to follow you, click:
Inventory :: Vehicles > Manage Piloted Vehicles > Select 11 Vehicles > Set Controller > Set NPC Controlled
- Prospecting Guide ”
Who wrote this guide? I don't even see an option for this so-called "Set Controller" page.
Simple method: When all of the vehicles are in one location, enter one of their cockpits, click Squadron, and add the rest of the vehicles to the squadron. This enslaves them to your lead vehicle (the one you're in) and automatically sets them as NPC-controlled.