Borussia Dortmund is a very good team. This is a team that have transfer structure, they don't just spend on player that don't worth. Though right now the club is going through a rehebilation process . They brought in Sébastien Haller, who scored couples of goals for the team .
Dortmund is actually one of the best teams in the German Bundesliga; they are always rated behind Bayern Munich due to their quality players and their experimentation in the league.
My only problem with Dortmund is their lack of consistency in keeping their star players in the team; they always mean business because if you offer them money for their best player, who is very important to the team, they will sell the player without having several thoughts. That is why Bayern is always rated above them in the Bundesliga. But right now, the team has signed some players and is building back their team in order to be a strong opponent for Bayern and other teams in the league.
Moreover they have the like of Marco Reus who is an excellent player to the team so I see them going far in the German Bundesliga this season and also in the UEFA champions league. Possibly winning it.
Having players like Marco Reus does give confidence in the team, and they are yet to lose any match, just that they drew two and won just one so far in the competition. I still see them among the title contenders this season because they have been doing it for several years, and I am sure this season will be another one.