I love IT and the 2017 season was extatic, the king in the fourths was so clutch IT was one of the most unprobable MVP candidate all time I guess. Right now Tatum of course didn't have a dominating season like that. But it may come sooner than later.
Tatum has an almost unlimited offensive potential. So if you think about their offensive talent, there is no comparaison. And Tatum is built to become an offensive minded top 20/30 player all time; he has everything for that. So not sure compaing them has a sense; but thinking about them at the same stage, about their tools and potential I vote Tatum without any hesitation.