The setback or bad play experienced by Dortmund at the start of this season occurred because several great players left the squad in the last few seasons because they were sold to other teams and it is certain that if a football team does not have players with good skills it will only stay in the same position the same or tends to be difficult to reach the top.
However, several top teams showed very good play and even showed their performance at the start of the season with full confidence so they could increase their chances and achieve victory.
Dortmund is a great club that is among the best in the Bundesliga, they tried to win the league last season but were defeated by Bayern Munich for chasing the trophy, I don't know why Dortmund is selling key players that will help them improve the club to glory and win many trophys, Manchester City buy Haaland and is a great player and skillful, he surprised everyone last season with many goals in the EPL and get Goldyboot. And even win the champions and premier leagues.
In my opinion i can say, they should not be selling the major players because it affects them, I am confident that if Haaland was in Dortmund last season, they would have won the league cup because he is a goal machine who can score at any time and is a talented player, however they have sold Bellingham to Real Madrid, who is currently playing well in the league and is considered one of the best players in Real Madrid squads.