Football is great because any prepared 11 guys with decent level can fight for a win against supposedly better teams.
This is basic cup knowledge, small teams will have a huge motivation against big names, so we can only put the blame on Tuchel for not putting his strongest XI OR to decide to play a full sub XI that want to fight for a starting spot in BuLi.
The pitch was horrible but this is also very common in cup games.
It really his is introvert personality that makes him unable to coach diva players - but if you give him 11 dirk Kuyt, Camoranesi, ngolo Kante and antistar world class players, I don’t see why he could not replicate his success in PL or Champons league.