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.
They have to more be consistent, Sadio Mane is very beneficial until the last week which means Liverpool certainly lost the style when Mane still was inside. So if they can change the style after, I think it's not a problem. In Latin football, Nunez has a bit different while controlling a ball when compared it with Mane from Africa, so we will see on the front Liverpool like Suarez again, Darwin could be a single attacker.