Love what we've gotten from Jaylen so far and I hope it continues. With that said, Tatum has the makings of go-to scorer in the NBA - from every position, in every way, with length, savvy, touch, feel etc. He's also 19 and is well beyond his years on that front. He'll have growing pains and many rookie moments this year, but he has a great future.
As far as which will be the better overall player - that's a more interesting question, IMHO. Still think Tatum could have the edge, but it'll be close!
Agree on your last point. I would love a starting 5 of Irving/Brown/Tatum/Morris/Horford.