Mane will adapt,and he will become one of the best players at Bayern,it's all time,he was doing very well at Liverpool,and he has alot of task to fulfill because responsiblities will be on him to fill the void left by Lewandowski.We all know it will really be difficult to replace Lewandowski,but with time,even if he cannot do exactly what Lewa did at Bayern,he should atleast be able to score a number of goals that will make the fans happy.
Another thing is that he hasn't really blended well to the style of play of Bayern,while Lewandowski has really hit the ground running at Barca,and he is one of the leading scorers already at the league.But I know with time,Mane will do well.
I'm not sure if Mane will be able to adapt to Bayern's fast and sharp playing pattern. If indeed Mane is a potential striker why did it take him so long to adapt, just look at how Lewandowski and Haaland quickly adapt to their new team because they are great strikers.
I see Musiala is more suitable to replace Lewandowski's position than Mane, currently Musiala has scored 4 goals for Bayern and I hope Nagelsmann puts Musiala in the position previously occupied by Lewandowski from now so he can adapt quickly.