This season has just entered week 6 so I think it's too early for us to measure the strength of a team or see its consistency.
Dortmund is still a strong team and I'm still quite sure they will be able to stay in the top 4 and regarding what happened in the Bundesliga this season we can see what happened last season and it is also possible that it will happen again this season.
This season the competition in the Bundesliga will be very different from last season because several teams that were less dominant in the Bundesliga last season will try to rise better until the end of this season. So teams that are often favored by many people such as Bayern Munich and Bayer Leverkusen will definitely feel a little difficult due to the rise of Frankfurt, Freiburg and also Leipzig. Because when there are several teams like that who are able to equalize the points with Munich and Leverkusen, it is clear that the level of pressure that will be felt by each team will increase.