By the way, I remembered my idea that Dortmund will play either in a great mood after reaching the 1/4 of the Champions League, or in a terrible mood after relegation. In both options, they should play well. Despite the fact that Schalke in recent games almost does not concede goals, theoretically they should return to the average result in the season - almost 2 goals per game. Perhaps I will bet on the victory of Dortmund with a handicap of -1 and odds of 2.46.
The handicap bet (-1) for Dortmund is quite good, considering that they certainly won't be able to score many goals against Schalke this week. However, Schalke really rarely conceded in their last 5 matches in the Bundesliga and only conceded 1 goal. On the other hand, with a record like that, isn't it too risky if you take the handicap (-1) for Dortmund to win, maybe if I may suggest it's better for you to take a handicap bet (-0.75) at least if Dortmund wins with a narrow score of 0-1 or 1-2 you can still get a half win and if Dortmund wins with a score of 0-2, of course you are safe with a full win in the bet.
I never make fractional bets and generally have a negative attitude towards them. This is a blur of ideas and goals, in this case, diversification is bad, because if you diversify your bet as much as possible, then the bookmaker will take its guaranteed margin and that's it.
I think it comes definitely down to whether or not Dortmund scores a fast first goal. Now that Schalke has only conceded one goal in six games, it doesn't seem to me as if it is still coincidence and not a fundamental change in their defense as you say. I think they are just better, which means that they are not necessarily going back to their average of conceding two goals per game. It can't just be luck if have five clean sheets in six games when before you conceded two per game. I did maths and it was even 2.5 goals conceded per game on average.
I am sure they must have done work to improve it. You can be lucky once or twice, maybe three times in a row, but is conceding one goal in six games still luck?
I tend towards Dortmund as well as any other result would be a disappointment for them. But there are now a couple of teams who thought it's going to be some easy three points against Schalke and then they couldn't score.
You are asking the right questions, but how do we know if the results are the result of improvements or a deviation from the average? One can only observe, but I would say that even if these are the results of improvements in the game, then random fluctuations will occur towards the average value. And in a game against a strong Dortmund, the likelihood of this is high.
