Just because you are in good form doesn't mean you have been tested against the necessary competitors. Unless you raise arbitrary numbers above all other possible considerations.

Bundesliga competition is fine (improving greatly every year imo) but it is not equivalent to la liga or the epl. Either Dortmund has to sustain this form when everyone else has rough patches, or they need to actually go head to head with the other big, in form teams in europe. This won't happen until we are deeper into the champions league.

Making this claim now is mostly meaningless. Man City has been massive and without a head to head result we can't tell who playing at the highest level.