2 years ago when I played RO2 and Enlisted is not out yet. I had some deep search of RO2’s historical places. It turned out RO2 is very accurate. Tripwire even went to Volgograd to make that game.
the source: Red Orchestra 2 Real Life Map Locations - YouTube
The Pavlov’s House
The Fallen fighter square
The street from station to the square
The station
The grain elevator
Volga bank
Mamaev:
And so many places…

To make this campaign interesting:
Provide authentic location. Create real (or semi real) landmarks.
Make 3D combat environment. Like Grain elevator. Set sectors inside the building, and put them at different floors!
Current Berlin maps are still to plain, still pretty 2D combat.
Set cap zone according to the building/area shape! Not just a circle or a rectangle. And make zone LARGE! So that we can fight INSIDE the building, not outside.
Even if we have to grind MP40 and PPSh again. But if you can give us a really different feeling of the game by really interesting map design. We still will love to play even if to grind same thing again.