Why don't people understand the difference between a director and a writer?

Ehren Kruger gave us Transformium.

(And I, for one, thank him for it.)

 

Only to a degree. If you posit that moving things into and out of subspace takes substantially more energy than moving parts around, it'd make sense for factions who were feeling the fuel pinch to use physical transformation to cut down on fuel needs.

Physical transformation might also be much easier to repair when damaged, as you're only dealing with standard matter, not dimensional warping. This robustness would make it more attractive in a military design.

Sure, a chassis which just hid 99% of itself in a subspace pocket would work well from a defense point of view, but if it ate energon like candy and was a pain in the ass to fix every time someone pinged it with a cyber-slingshot, it might fall by the wayside as a valid battlefield design over a couple million years of warfare.