I thought that with a body on frame design, like the VX, that the doors didn't really give it any structural rigidity. Since the weight of the body is sitting down on the frame it shouldn't matter if the doors are there or not. Even if they are there it doesn't seem like they would contribute much rigidity as they are really only touching the body in three spots (two hinges and one latch.

I've seen a couple of Rodeo's out in Moab without their doors and they don't seem to have any problems.