With any of those oil pumps that hang on the end of the crank there is a tendency for them to take a while to drag up the oil after sitting a while. cranking is the hard way because if it was just started the oil would be up there a lot quicker. In some cases the starter might never get the oil pump to prime.If you are that worried you can always pull out the pressure relief valve and plunger, then squirt some oil in the hole while hand turning the engine backwards. That will wet the pump rotors and help a lot, rover v8 is another example of this you have to pack the thing with vasalene to get them to prime from new and if you dont the pump will be shot before you start.
http://www.roversd1.info/3500/oilpump.html in the oil pump refit section.
Bob . Edit sorry mike we were typing at the same time.