Whether you go for DB or DR or both (what ever your interests are) for me it is a marketing stunt by any model train producer to produce the same loco for different Railway companies and to some degree since the nations of Europe are what one could call: unified, Märklin and other producers have benefited from it.
it is a matter of money, taste and choices how many railway companies you include into your collection or layout.
I myself, have started mainly with DB locos, than Austrian, Swiss, Dutch and French. over the years I've realized to keep it up it would be a money spinner for the sellers but I could see the outcome in the end so I culled my collection to DB, ÖBB, SBB and SNCF with a couple from SNCB and 1 FS diesel loco.
Historically it is again another story to compare the 2 railway companies before or after the war and one can say even when the wall was removed east Germans felt inferior against their counter part from West Germany.
Having said this many companies including railway depots etc etc. had been scrapped after the unification putting a strain on employment opportunities.
Working for the railway in East Germany. and steam was kept much longer than the West, the existance to work would have given these people a formal security and most probably an insecure status after the unification.
the ordinary East German worker had what they needed to live and the Comminist regime gave them this security it didn't go anywhere, it didn't make any profits or gave them browny points except choining the party.
How both sides railway workers had been integrated into another railway system, corridor or similar work, I don't know but what ever working and living standards both sides had would have been adequate.
Even if you look at the West, not everything is rosy and this is what the Eastern People thought, there will be a new live, prosperous and rich, they soon found out it wasn't all cake and the icing soon dropped off.
I don't think there is much difference between a railway worker in Germany or Thailand both have a certain expectance from live and both are happy to be a live.
If you take for instance the english railsystem , most of the followers and worshippers of steam in Britian are older people, who lived, who worked, who supplied, who travelled, who adored the ingeneering skills of their anchestors including bridges, tunnels and the locos them selves.
and one could say it stood still for many years without any modifications or improvements, the governments spend their money on roads.
to find something extra ordinary in the past history of both East and West Berlin is from the person who has certain living standards and is trying to apply these to a culture who do not live on a point scale.
Education is one of the important lessons any country can benefit from and from an economic point of view, each country has their own economic culture, it may be Western or Eastern culture or religion, the question I ask my self is, who benefits more from what.
If I would look at the Austrian railsystem and integrate other railsystem into my layout, this would mean: Hungarian, Slovenia, Italy, Switzerland, Germany, Chech Republic and Slowakia.
or one goes back to the Habsburg empire:
The Kingdom of Croatia (1527–1868);
The Kingdom of Slavonia (1699-1868);
The Grand Principality of Transylvania, between 1699 (Treaty of Karlowitz) and 1867 (Ausgleich)
The Kingdom of Galicia and Lodomeria, in modern Poland and Ukraine (1772–1918)
Duchy of Bukovina (1774–1918);
New Galicia, the Polish lands, including Kraków, taken in the Third Partition (1795–1809);
Venetia (1797–1805);
Kingdom of Dalmatia (1797–1805, 1814–1918);
Kingdom of Lombardy-Venetia (1814–1859);
Kraków, which was incorporated into Galicia (1846–1918);
The Voivodeship of Serbia and Banat of Temeschwar (1849-1860);
The Kingdom of Croatia-Slavonia (1868–1918);
Sanjak of Novi Pazar occupation (1878–1913);
Bosnia and Herzegovina (1878–1918)
regards.,
John