Mitchell should be ahead of Tatum as far as RotY goes, but not a hypothetical re-draft.
Tatum was widely considered to have the highest floor of anybody in the draft, but people seriously underestimated his ceiling. I believe his scoring will become elite, his defense and rebounding could be a major plus as well.
Mitchell has been spectacular in a role tailor-made for him. He deserves Rookie of the Year. But Tatum will have the better career, and I’d be surprised if it’s even close by the end of their rookie contracts.