Simple question: would you allow Field Commander (and improved version) to be used on vehicles? As written it looks like is only intended to be used with characters, but the tactic opportunities that it offers with ships and vehicles are great (and it's part of the squadron leader talent tree)

My take on this, is that in the case of a Squadron Leader, Field Commander would usually involve the ships and vehicles. The actual maneuvers (and action, in the improved version) would be taken by the PCs and NPCs involved (pilots, drivers, gunners); but the specialization is intended primarily for vehicular command.

The same Field Commander talent in the Tactician tree (boots-on-the-ground) would primarily focus on influencing ground maneuvers.

Tactician can be in charge of a vehicle platoon, like tanks. In my campaign one of the players is a mix of Driver/Tactician, and this talent will heavily help him to command his fellow vehicles. But I am not sure if there's something, RAW speaking, that will prevent him to do so. In the starship section, when you spend disadvantages you have the option to provide an enemy a free maneuver that can even exceed the limit of 2 maneuvers/round, and I understand this maneuver doesn't have any strain cost. I guess Field Commander is similar?

Personally, I would pick the Squadron Leader spec for a tank commander- talents are better focused for vehicular combat benefits:

• Let's Ride
• Defensive Driving
• Full Stop
• Tricky Target
• Form on Me
• Brilliant Evasion

The Field Commander "suffer one strain to perform one maneuver" seems pretty straight-forward to me. It does specify that this counts as a free maneuver, and not against the typical allotment.

I would rule that if the free maneuver is used as a Vehicle Maneuver, it doesn't count towards the maneuver limit for vehicles either. Squadron Leader is the vehicle commander specialization. Mixing that with a Driver/Tactician could create a pretty potent Vehicle Commander.