Technically the Vigilant and Vanquisher are Main Guns, which cannot be wielded, only mounted. If they were mere Minigun versions, their damage wouldn't be by far superior to the normal machinegun ones. The Vindicator, on the other hand, comes with stats identical to other LMGs. Any MMG/HMG minigun version would reasonably use the 6P/-2 and 7P/-3 while using Full Burst rules (and possibly also a Simple Action to get to full speed, which one might demand for the vehicle main gun miniguns too).