This is very correct about Ten Hag, he did same with Manchester United and Ajax, but the most he has done was with Ajax, at Manchester United it was only in his first season they got to see him perform well but by his second session he performed poorly yet he won a trophy. Here he is in the German league, knowing how competitive this league can be, I trust he is going to learn from his past and try fixing a better performance with his new team and maintain a good track record that will last longer than he did with his former teams.Ten Hag isn't a bad coach by the way, he only had some rough edges with previous teams in that after his first seasons, his systems begins to collapse of which in some cases, players exit was responsible.
Ten Hag may not be a bad coach. But Ten Hag is not a very experienced coach. Ten Hag was successful with Ajax. But he failed with Manchester City. Manchester united management was given big funds and enough time to Ten Hag. Even then he could not play much role in improving Manchester United's performance.
Leverkusen management has given ten Hag the responsibility as Xabi's replacement. We do not know if Ten Hag will succeed. However, His past record is not that good. He must learn from his previous mistakes. Otherwise, Ten Hag will fail in the Bundesliga as well. Leverkusen does not have a lot of money. So Ten Hag will have to try to stabilize Leverkusen's performance while keeping the squad almost unchanged.