Good luck to him. If he does as well as Southgate he'll be well regarded and seen as a great appointment!
IMO, Southgate's best achievement was to get a cohesive, forward looking squad out of a team and squad that become a jaded joke. Players turned up reluctantly or not at all, saw the quarters as an achievement, and too often I thought they would rather not die on the pitch for each other.
He put all that right. I thought he was too cautious in the very big games, particularly the 22 final, when I thought we should have won. But he improved us dramatically.
If Tuchel does get to a final, or semi, his real talent should emerge, as he is extremely good at big games.