Even i am a big fan about Füllkrug and Haller i guess that one of them will be leaving the Club.
Donyell Malen and Guirassy together can be very good combination for Dortmund to get fast forward on the field.
Dortmund continues to strengthen the team, it’s a pity that they were left without Terzic, but apparently he played his role in this team. All of Dortmund's new transfers look very good as always, and this is not surprising, they have long been famous for this. But I suspect that they are doing this not with the aim of trying to become a competitor to Bayern in the Bundesliga, but as part of their strategy, when after a season several of their new acquisitions were able to fulfill their potential and will be sold to other teams.
I also always admit that Dortmund has never run out of great players but unfortunately, Dortmund prioritizes business with the profits it gets when selling players. Although Dortmund at least has an effort to win the Bundesliga trophy with competition with Bayern Munich, but Dortmund also quite often sells its key players to Bayern Munich. Thus, it will certainly remain difficult for Dortmund to get the Bundesliga trophy.
Indeed, last season Dortmund also got great results because Dortmund played in the Champions League final but still, basically Dortmund still needs to be consistent with key players who must be retained and not to be sold just for business purposes. After all, it is proven, if the team is able to maintain its key players of course there will always be a chance for them to get the trophy, like Bayer Leverkusen.