Cows don't roll - they are frictionless so just glide over the surface smoothly.

Spherical cows on the other hand have to move with orbital velocity at least, or they fail to stay in vacuum for long and splash.

Not with that attitude

It takes a stupid cow, but when they can climb mountains as they do it is not inconcievable that one can roll down.

(I was suprised to see a cow jumping up on a ~3m rock ledge like it was nothing)

Or on shabbos