Although I haven't actually done this experiment, it certaintly seems like delivery affects pitch break. During my franchise run, submarine pitchers always have me hell. There aren't that many submariners out there, but their pitch breaks are so unpredictable. Even fastballs seem to have some weird downward motion 5 feet in front of the plate.
good call on the Randy Johnson clone. In my opinion, he's the most dominant pitcher of all time. I still remember as a 7th grader watching him own my Yankees in the world series. Simply the best ever!