As said before it's about supplys where are the people from dc going to get the supplys to survive and keep shooting
The whole idea of the situation was if everything from the CW was dropped into a place with everything from the Mojave and they fought each other. You can't really bring in things like supply trains in such a concept.
Besides the NCR would have just as much trouble if not more (they can barely keep their troops in the mojave supplied).
also mojave had DT which is far superior compared to DR
Can't really go by game mechanics else the CW would win hands down with the multitude of essential characters who don't die