I agree that Serhou Guirassy showed an impressive very good performance last season and that Dortmund was very lucky as there was a few other Europe Top Clubs to get Guirassy.
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.