Going to trust you're right about those #s, very well done.
I think that's a great indicator of the ceiling, but not a good indicator of who would actually play more minutes right now. There's still a very good chance Green is a better NBA contributor than White on day one, but there's a much less likely chance of Green ever becoming a more dangerous starter at any point.
Another thing that really matters is personnel of the team and injuries. Any player not taken in the top 15 or so really needs some breaks in the personnel and injury departments. The first half of the year the Bulls first round pick Jimmy Butler and journeyman John Lucas III (Ok State) played pretty much zero non-garbage time minutes. When Rose and Watson were hurt at the same time they both suddenly got a ton of minutes. Butler didn't really win himself more minutes when the team is at full strength, Lucas did himself major favors and will be getting minutes with the Bulls or some other team for at least the next year or so because of his play.
Who knows what might happen with Royce's situation. Brackins keeps coming up, CB may be an injury away from proving he does or doesn't belong in the NBA.