So I have a question.

If I used the three required slots for a supply truck, ambulance, and super heavy tank, could I in theory fuse the three vehicles into one super tank base thing? I personally am enamored to the idea of needlessly huge vehicles with piles of dakka and even some living space, perhaps due to Mad Max, or the orkish battlewagon, but regardless.
May I have a single vehicle, which takes up two support and a heavy armor slot, that is a supply vehicle, ambulance, and super heavy tank? Ah, and of course I'd also have the doctrine for super heavy tanks as well of course.