The efficiency of the German railways

At the start of this trip I described it as a trip through Europe thanks to Deutsche Bahn.  And indeed, that is where I booked my journeys through and given that every train starts or ends (or both) in Germany I would have expected this to be the case.  However it has not.

Berlin to Warsaw was by the Polish railways.  This is perhaps understandable as the vast majority of the trip is in Poland.  Prague to Dresden was by Czech Rail.  Again, the majority of the route was in the Czech Republic so maybe understandable.  (The train itself was mainly Czech but had one German carriage at the end of it).  The trip from Dresden to Berlin... that was Czech Rail again!  It is a continuation of the route from Prague, but it appears that the majority of trains along this route are of this style.  However, whilst the trains are from different countries, the staffing always corresponds to the country you are travelling with a “changing of the guard” at the border.  On the train to Warsaw this also meant a change in the nature of service with a free cup of tea and coffee even in standard class!