Quote Originally Posted by Lord Liaden
In order to make it easier to balance the Invid against the piloted mecha of their opponents, I'd suggest building them as Vehicles with an AI "computer" guiding them. You could assign them a Vulnerability for increased BODY damage from shots which hit the eye. The optional Hit Locations for mech vehicles from The Ultimate Vehicle would probably help you with this too.
I would rather build them as mecha with a pilot, and maybe give the mecha a limitation Pilot dies if takes more then x damage in hit location-sensor eye.