Yes, well...

... my personal explanation is that Lahm, Mertesacker, Badstuber, Schmelzer, Bender, Schweinsteiger, Khedira, Gündogan, Reus, Özil, Klose, Gomez, Schürrle and probably a couple of others I can't think of right now are missing and that the replacement players lack both experience and practice in playing together.

But I'm open for other theories...

DOOOOOoooMMMMMMM