Ten Hag have had experience in this league before so there's chances that he could do well, I'm not going to conclude until I see how Leverkusen would perform in their first 5-10 games until then Dortmund are the only team I feel can challenge Bayern Munich even though I doubt if any team would take away their dominance like Leverkusen did when Alonso was there. Well with the squad Xabi left for Ten Hag getting into the Champions league shouldn't be a big deal.
Bayern Leverkusen squad are not that bad even though some of them have been sold out to other teams for the continuity of their careers there. They were still able to finish as runner up last season when Xabi Alonso was still in control of the team, this shouldn’t be an issue for Ten Hag to make that qualification every season because he has the squad that should be able to pull that through for him under his good management. I don’t doubt Ten Hag capacity even though he happens to not finish the season well at Manchester United when he last managed them and was sacked. This is a different club, different league and a different challenge, he should also develop here with time and could be at his best here than he was at Manchester United.