If Leverkusen fans do the same thing they did when Ten Hag was at Manchester United, I don't think Ten Hag will develop. Therefore, Leverkusen fans should give Ten Hag time to build a strong team, and certainly shouldn't expect him to compete with Bayern Munich for the Bundesliga title in his first season at Leverkusen. A top-three finish for Leverkusen was a good achievement for Ten Hag in his first season. Fans can expect more from Ten Hag to win the Bundesliga trophy in his second season.
That's just a fan's hope, but good results for Leverkusen are possible in his first season as long as Leverkusen has the best players capable of outperforming Bayern Munich's players. Because Munich has truly dominated the Bundesliga, there's a huge difference compared to the Premier League. When Ten Hag was managing Manchester United, he wasn't supported by better players, especially after Ronaldo's move to the Saudi Arabian League, which led to Manchester United's even worse season.