The new manager faces several disadvantages. For example, he won't be able to sign the players he wants because the transfer window has closed. He will also aim to be a tough opponent for Bayern Munich in Germany. Knowing that expectations are high, he will strive to succeed with a squad he didn't build. The new manager will have a truly significant responsibility. Appointing the Dutch manager from the start was a complete mistake. I'm sure the management has realized this by now. This mistake could cause problems for Bayer Leverkusen until the winter transfer window.
The transfer window will reopen midway through the season, and perhaps that's when the new coach can capitalize on the situation to buy some desired players. For now, he really needs to utilize the available players. Although it will be difficult to compete with Bayern Munich with the number of players they have, if the coach is at his best, keeping up with them and not falling behind is his primary task. It certainly won't be easy for the coach, but there's no choice but to keep the team on the right track to winning the the match they played.