Bayern Munich are also starting to build their squad after a less than impressive performance under Tuchel, Stuttgart will also try to provide competition after finishing below Leverkusen last season. The competition in the Bundesliga is getting more interesting after Bayern Munich dominance was broken, now there will be other teams who want to follow in the footsteps of Leverkusen who have just won the Bundesliga. In my opinion, Dortmund still has the capacity to enter the top four, but the chances are very small.
Indeed Dortmund with their new coach will have a little difficulty but I don't think it's excessive.
Leverkusen and Bayern Munich will still be the favorites to win the title this season and I even think the competition this season will be much fiercer because Bayern Munich made many changes in the team.
And overall the competition in the Bundesliga has been quite fierce in the last few seasons we can see that the Bundesliga is getting more competitive.
I agree with you that it won't be difficult for Dortmund to stay in the top four of the table and qualify for the Champions League. However, this team does not seem to be able to compete for the title. Moreover, Stuttgart performed well last season. Indeed, the team will be looking to finish in the top four of the table to qualify for the Champions League again.
Undoubtedly, Bayern Munich and Leverkusen will fight for the Bundesliga title. Bayern Munich team is not stable now. With the help of new coach Vincent Kompany, Munich's performance is still not stable. On the other hand, yesterday we saw the Leverkusen team lose by a huge margin of 4-1 in a friendly match against Arsenal. Xabi Alonso will now have to step up to strengthen Leverkusen's defence.