Does it really matter? In some ways, probably not. Think about this ....how many revolutions does the camshaft make during the entire assembly process, going thru the valve lash adjustment process, then the engine assembly installation process, and finally the initial start-up.
Would it be fair to say most engines will see in excess of more than 10 lobe revolutions across the face of each tappet? If so, how much assembly lube/white grease/moly lube will still be there after that 10th revolution?? Granted that 'something' is better than no lube, but in all likelihood there really won't be much lubrication to make one coating better than something else.