Got sacked by Dortmund didn't he? Also got embarrassed by Liverpool in the Europa league.
As for Aubmeyang, Klopp signed him and he scored a hatful of goals before Tuchel ever got his hands on him, 25 in his previous season. Tuchel is one of those overhyped guys who achieved nothing and yet for some reason is flavour of the day, a tactically astute manager wouldn't have seen his side lose a game to Liverpool when they needed 3 goals to go through. The guy inherited a top quality squad from Klopp, he did a mediocre job with it, crashing out of the CL then embarrassed in the Europa.
If Bayern didn't exist Dortmund would have won the CL as well, but they do and that's what you're up against, the fact is their record under him in Europe was poor and even domestically it wasn't great, like I said ending up third 18 points behind Bayern pretty poor IMO, even the season before they were 10 points behind.
Overrated doesn't begin to describe him, he's a nobody that got lucky and got a chance at one of Germany's biggest clubs and messed that up big time, the guy achieves nothing and yet is apparently the 2nd coming to some, do me a favour