I didn't say Erik Ten Hag and Vincent Kompany have the same coaching qualities and skills. I don't know where you get that impression from because I didn't even mention Erik Ten Hag in my post. No, Xabi Alonso didn't have the quality of players Bayern Munich has when he won the Bundesliga title, but Bayern Munich was in a mess and struggling to win their matches at the time Xabi Alonso won the Bundesliga title, which was one of the reasons why Xabi Alonso was able to beat Bayern Munich in the race for the Bundesliga title last season.
Bayern Munich and Bayer Leverkusen are not the same thing. One of them have been consistent for years in winning games and lifting trophies while the other have been delaying every slide moves, but make good use of one season where they got managed by Xabi Alonso. Who's a genius and help them achieve the bundesliga title and other accomplishment he made. But it's definitely going to be a long term to see Bayer Leverkusen back to their prime, they let go of their manager, and also key players. Then I ask again, how will they survive next season?
Erik Ten Hag is entirely different from other coaches. Go and ask questions when it involves Erik Ten Hag. He always ensured he lifts a trophy for Manchester United despite his poor stats for the club in a specific EPL season.