Overall, yes, if Mane leaves it won't have much of an impact on the team, but there will be a re-adaptation in the front sector because it puts new players in. Nunez's arrival was for that, to fill the void left by Mane. So Liverpool have signed good players to replace good players. I hope Nunez can quickly adapt to the Liverpool game.
I am sure Nunez will be able to adapt to the Liverpool players because the Liverpool coach knows which position to put Nunez in and the Liverpool coach will also not make a difference to Nunez so Nunez will be easier to adapt to other players and will also feel more compact with another for a team.
Nunez is a young player and he has done very well with Benfica, I have no doubt that Jurgen Klopp will be able to make Nunez develop and adapt quickly to the Liverpool players.
since being coached by jurgen klop now Liverpool are much more characterful and when there is a rotation in the team it will still run well, as has happened with several new Liverpool players in recent years who are able to adapt quickly, I think Nunez will too.