Let's look at the bottom of the table, there are 3 clubs that have the same points, Mainz, Koln and Darmstadt who have 10 points each, ranked next is Union Berlin who has 13 points. It looks like the competition at the bottom is no less interesting, they will compete and shift each other until the end of the season.
Bremen and Bochum who have 16 points cannot be said to be safe, the article with the number of matches that still exist now it is very enough to catch them, especially if they lose a lot of points.
Focusing on Union Berlin, they are a club that has failed to perform well this season, after last season they could compete in the Bundesliga top 4 competition. The decline they experienced was so sharp that it put them in the current position, in a position that is very vulnerable to relegation.
It's quite interesting to see the competition between the three bottom teams in the Bundesliga this season and maybe the results will change when half the season starts. These are only temporary results and surely one of them will creep up. Here I quite favor Mainz because this team is actually still able to get out of the relegation zone and even though the results in the middle of this season are less than satisfactory, I think they are still capable of finishing in the middle of the table.
On the other hand, it is possible that Werder Bremen and Bochum are closer to the relegation zone or even relegated considering that both of them have always finished at the bottom of the table in the past few seasons. I don't doubt that and they shouldn't experience the same season and get to know this competition better so they don't stumble into the same results.