Calling this a generous coefficient is a bit too much I think, but yes this is also owed to the fact that Dortmund is quite inconsistent at times. They have had some good results now for a while, but all too often they fall back into their weak game again and also make massive individual mistakes. As this will be punished by Bayern more than by any other team, I think the odds are about fair. Frankly, if I had to place a bet, I would probably go with a tiny bet on a Dortmund win although history proves me also wrong I think. I can't remember when Dortmund won their last game against Bayern in Munich.
I checked and Dortmund won their last game in 2018 at home against them. And it was in April 2014 when Dortmund won their last game in Munich 3-0. Ok, my hypothetical bet would likely fail
but that is why the odds are the way they are. The match between Dortmund and Bayern Munich would definitely be in favour of Bayern Munich even though they're sharing same points currently, Bayern Munich got a better squad and are more stronger and if you judge from the previous meetings 2018 is in a very long time and I don't think Dortmund would be able to win them.