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.
Actually Mane has already adapted to the style of Bayern Munich. His scoring 5 goals in 11 games so far must be a good proof for this. Mane is really a special player for every team he joins. After he left Liverpool they felt this absence too much very quickly. They are still feeling his absence though because his role was really crucial for the productivity of the team.
Now he might be the player who Bayern Munich mostly rely on now. Because they still don't have a striker and they are hopeful about their attackers to be better at scoring. Mane is trying his best but this can't go on like this. He should go back to his natural role as soon as possible after transferring a striker.