We will see if Liverpool really made a mistake by selling Sadio Mane. It is still early to make such predictions about the situation. As I said before, it is depending on how the new trio will play and how Darwin Nunez especially will play in this season. Liverpool got really close to a championship in the league last season but lost their chance by inches. They need to put a bigger effort into it this time to be able to get ahead of Manchester City. They will need to decrease the amount of points lost in easier games to make a difference.
Just 2 or 3 games and fans are already tearing Nunez apart for his poor performance and lack of goals in the pre season matches. I think he should be given more time to adapt in the team, hopefully he will blend in and the team will play even better and be able to match the league champions and rivals Manchester City. I think by now they are done with transfers this summer and will now focus on building the team to play together.