Dortmund didn't have a hard game against this team and they're totally unknown, however, Drtmound and all other teams are in the training phase and they are mostly not ready for the games otherwise they could even win the game with better results. I think the thing Dortmund left do to for this season is to find a better replacement for Bellingham they sold to Real Madrid.
Dortmund is a team that very often sells the best players they have printed and almost every season is like that. I think it will not be difficult for Dortmund to find a replacement for Bellingham which they sold to Real Madrid, because selling the best players is like a business for Dortmund so I will never be surprised when in the future Dortmund sells the best players again after they have trained them with pretty good. Likewise with Bellingham which they have sold to Real Madrid.