I won't say it was a mistake letting Lewandowski go in the summer because at the time the situation was out of their hands, Lewandowski wanted a move and for the long time been with the club it is only normal and an act of respect and gratitude to grant his wish. Mane coming in was a good move and I expected he would fit in immediately and cover up for Lewandowski.
Not mistake made by Bayern let her go Lewandowski to Barcelona because left one year contract only and keep extended until his contract over, Bayern can't earn almost 50 million euro from Barcelona. I think Bayern smart here because got service from Lewandowski success bring many trophies from Champion League until several time Bayern dominance get Bundesliga trophy, but Lewandowski have final decision won't extended contract with Bayern left 1 years later. Actually become opportunity for Bayern trough have offering from Barcelona with most expensive values.
Totally Bayern earn much money because Lewandowski get free from Dortmund after not extended his contract.
His only 2 options at the moment are to take advantage of the sale of Lewandowski or force him to hold Lewandowski on the condition that he will leave as a free agent.
Bayern know when this is forced it won't go well because Lewandowski has often said he doesn't want to be at Bayern anymore and of course that kind of money is definitely an advantage in my opinion for Bayern.
Bayern's performance was not too bad so far, especially in the Champions League.