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.
Terzic is a great coach who has shown expertise in managing the team. Last season Terzic was able to bring Dortmund to the final of the League of Champions but unfortunately Dortmund lost to Real Madrid. Next season, Dortmund will be coached by their new coach, Nuri Sahin, so in this transfer market Dortmund certainly looks quite active because they want to overhaul the team to be stronger by recruiting top players. They managed to bring in one of the productive strikers and it is likely that there are several other players who are ready to be brought in so they can compete strongly next season.
Both Dortmund and Bayern Munich of course started this season with new coaches who were appointed by management at the start of this season. Nuri Sahin and Vincent Kompany will compete to bring their team to become champions this season. But I think Xabi Alonso still has to be taken into account by other teams because Xabi Alonso makes Leverkusen very strong and allows Leverkusen to repeat its great success this season.