in this case Mane can still carry out his duties in the same position as Lewandowski but on the other hand it would be very good if Kane was also there.
Regardless of anything Bayern, if they really want to contribute more to the Champions League, they have to try as hard as possible and that can be obtained from Mane and Kane, whose performance in the Premiere League has been tested.
Mane is quality player, and he can do just like Robert Lewandowski done in past for Bayern Munich, and they already have few other signings as well but still having interest in Harry Kane is no bad at all but with this all most chances this is surely no possible in this season because currently Tottenham is also in good shape, and they are investing good amount for having more quality players which can bring good results for them in presence of Conte so if Harry Kane leave this could be big concern for them and their strategy.
Most chances this transfer can happen after one year because currently they are also in good shape for winning title and having better chance in Champions League as well.