Sphaero. You miss Reus. I am not talking about Gündogan as he was not there last season. And not about Lewa because he is not available and you have 2 new players for him. And Lewa last season was not the killer in such matches either. You should know better than me. I have seen a statistic around winter in which they listed the participation of the strikers on decisive goals - and Lewa was down in that list with only one or to of the main strikers of the Bundesliga behind him. That might have changed later on - but was like this in the first half of the season. (that stats made me doubt if Lewa even if I see his technical qualities is really giving us the edge, I do not think that today was the match to show anything different as Hannover was just offering everything on a plate)
Dortmund last season had by far more goals like the other competitors (I let Bayern out of it) but had a little less goals out of open play as Gladbach, Schalke or Wolfsburg had. The difference often (it is not about the last weeks in which Reus had great matches) were goals after set-pieces, counter attacks and the penalties. That is were Reus is really missing. He is just great with his corners and freekicks.
OK, first off if you want to tell how I should no better about my own team, you should check your sources better, because what you claim in the bold is factually wrong:
club/total goals/set pieces/open play
Dortmund: 80/29/51
Schalke: 63/16/47
Wolfsburg: 63/21/42
Gladbach: 59/don´t know the total number, but Nordveidt assisted 5 goals via a corner and Kruse converted 5 pens so at most 49
Now, I´m not going to dispute that Reus is our best offensive player, especially when it comes to breaking up defense lines and set pieces, but you make it yourself pretty easy here by pinning everything on his absence. You wanna know who the back up corner and free kick player for both Schmelzer and Reus is? Sahin. He is injured. The 3rd? Mkhitaryan. Also out.
Speaking of Mkhitaryan, you completely ignore him. If you don´t see his worth, fine, I will tell you. He is by far our best offensive pressing player and also the strongest in terms of general defensive contribution. His injury actually hurt us the most in the current state. With the shaky back line and disrupted CM/DM he was extremely valuable because he took a lot of pressure from them and gave us some much needed stability. He also created a lot of space offensively by binding opposing players. The results of his absence are bloody obvious.
Kuba gets also no mention, when our Polish right side was one of our most outstanding features if both are fit. There is nowhere else such a clear and strong synergy of two players in the squad.
Ji was basically signed as a relief option for the starters and both Großkreutz and Aubameyang could do well with a break right now, especially because both don´t play in their best positions right now because of the lack of alternatives.
In the CM I´m not necessarily speaking of Gündogan. We played well without him last season, because his replacement did a very solid job at filling the void. Despite what some might think Nuri Sahin played a good season. He rarely did something outstanding but aside of a three game spell in the last winter did what he was asked to do. He build up the game reliably and structured our game. On top of that he is our best CM in terms of defensive matters. His absence also hurts us, but would not be as bad if our third clear cut CM could take over.
Oliver Kirch made a surprising and impressive jump in his development despite his age. He continued where he left of in the Pre season, being our best and consistent player next to Mkhitaryan and Aubameyang.
We went into the season with three options for one position and all of them are injured. Instead of them we are forced to either play two DM next to each other or an out of form midfielder who is clearly better as AM.
I´m not going to use these injuries as sole reason for our poor form in the league, but if you think that no injury besides Reus´ matters, you are simply mistaken. We are not some kind of one man team and far less dependent on a single player than other teams.
I´m also honestly tired of this argument of our lack of a plan B vs. smaller sides in a normal state. There is nothing objective to back it up. Yes, we intensified our focus on set pieces, because they are an effective tool to open up the game. There is nothing wrong with it. I posted the results and statistics from the last season before and not gonna bother to do it again. It appearantly does not matter and if it makes you sleep better to think that, fine. After all "I should no better than you", right? Well, I actually do.