Last week Hertha Berlin beat Stuttgart by 2-1 and not Mainz but yeah, maybe it doesn't really matter because in reality even though Hertha Berlin is at the bottom of the table but Hertha Berlin still has the ability to win too. So yes, playing against FC Koln is of course an important match too, because based on the head to head record it looks like Hertha Berlin has good dominance when Hertha Berlin plays against FC Koln.
I don‘t believe that Hertha BSC can win the game. The win against Stuttgart last week, that was good for motivation, but Stuttgart is not an extremely good team in the Bundesliga. I wouldn’t compare them with FC Köln, they are a better team at the moment, they won against Leverkusen last week. Today there should be three points for FC Köln and then there are only two match days left in this season. There is also an anniversary today: Florian Kainz is playing his 150th Bundesliga match today.
In terms of rating, Hertha Berlin is a bigger club than all those teams u just mentioned. If u want to know more u can check the records of Mainz, Stuttgart, and even Cologne they will be playing by the weekend. Hertha Berlin is a well-known team in Germany who has been very outstanding in performance some years back. u will agree with me that even though the club no more has the charisma it use to be, it will not underperform against these little clubs that just gained strength recently in German football. When playing against Cologne, Don't be surprised when u see the score board in favour of Hertha Berlin.