IMO it's Mitchell. Simmons has a great supporting cast for his talents, Tatum is going to get so many open shots and good looks with Hayward and Kyrie returning, Markkanen is getting more help in Carter Jr, and Kuzma will be getting passes by the best player in the league.

Mitchell will be good again but I doubt that he can replicate that performance in the stacked west. It was an awesome story seeing him replace Hayward and leading the Jazz to the playoffs but it would be extremely difficult to play that well again as the focal point of his team's offense. I think he and Tatum will end up being the best players from that draft class though when they both retire!