An open diff rear is not one wheel drive. Its either two wheel drive or zero wheel drive. If you have traction both tires put equal power to the ground. If you break one free neither tire puts power to the ground so its zero wheel drive
Sorry, but you're incorrect. Get stuck with an open dif and see how may tires turn. I guarantee you it won't be two or zero.
Or ...
Do a burn out with an open dif and see many tracks it leaves.
