[Lil' Lavery]

Originally Posted by Alan Anderson

The two possibilities have very different turning behavior. Imagine the equivalent omniwheel drivebase with the wheels in an X shape instead of a diamond. You simply cannot turn yourself in place using that arrangement, but you also cannot prevent yourself from being turned by an outside force.

Good point, I hadn't thought about applying a torque to your robot. I was thinking translational pushing, in which case the two configurations are the same.