Servo-less steering idea

BTM

I had an Idea for servo-less steering a while back, as a way to steer tanks and such. I though up a way to steer a tank using only 1 joystick, but I haven't had any time to test it, as I model with a mac. I'd like to see if anyone can test it to see if it works.

Here's my idea:
Shows how the vehicle would be controlled. Middle controller shows how it would work, with both other controllers overlapping. (colour coded)
Every wheel would have 2 motors: one along the Y axis, the other, the X axis (of the same Joystick).
All wheels would have the same motor controlled from the Y axis, but the motors controlled by the X axis would be the opposite on the left than the right: one side would have Max. Axel be in positive value, the other side would be negative value.

What I'd expect this to do is that:
when you move the joystick left, the left side of the vehicle's wheels would slow down, and the right side would speed up, so the vehicle would turn.

Obviously I don't know if this would work or not, but I hope someone else can figure that out.

It would also be extremely helful if someone managed to have it so that the red areas were "Reverse" instead of "Stop".