For Bayern Munich to win Dortmund it is a big win for Tuchel, atleast his first game as coach of Bayern Munich came out with a good result. The victory of the game will give fans good impression of Tuchel winning more games in Bundesliga and in Champions league. Interesting for Bayern Munich to maintain the top position.
More challenging matches await Tuchel in the Champions League. Borussia Dortmund can be a tough team, but Bayern Munich managed to overcome it. They are currently leading the league and will manage to keep it. After Nagelsmann, this match was very critical. Had they been defeated by Dortmund, they would have been heavily criticized.
luckily that didn't happen. the match proved that there are no problems with the current squad. and Tuchel will make it even better. in the Bundesliga Munich has no problem with its competition with Dortmund. one of the other challenges for Tuchel is to face City later. it's not an easy matter but I'm sure Tuchel has some tactics to reduce the risk of a big defeat against City's excellent front line.
We'll see, whether Tuchel's luck is good this season.