Through the 10+ games I've seen of Bagley, I have never come away with the idea that he could create his own shot.
You are wrong about this! Marvin does the euro-step like a guard! He's a savant at positioning himself to finish, thats his game.... He doesn't get tested that often so it kind of just looks like utter dominance.
Duke wasted so much time, and frankly their national title chances, letting Grayson Allen run the offense, and various other mistakes Coach K made with that roster throughout the season.
Marvin's arsenal of moves aren't like your old style post moves because he doesn't need to get you off balance or bowl you over with strength, he has the athletic advantage, he can simply go past you or over you and he is capable of all sorts of high degree of difficulty acrobatic finishes, plus if he misses close to the basket his 2nd jump is catlike up for the putback.
He's a space eater offensively. in that lurking dunk position right outside of the paint (1 foot in) on the baseline Bagley is a dangerous weapon for the Kings to have, If Fox beats his man on the perimeter it's gonna end up as a Bagley bucket or foul, a lot.