Here's an interesting AHC for you: Have a much more populated Baltic region. Specifically the territories that are now a part of Estonia, Latvia, Lithuania, and perhaps Kaliningrad Oblast. If you will look at this EU population grid map, you'll see what I'm talking about here:
The Baltic region simply doesn't have all that many people nowadays, with the exception of a few major cities. Certainly not in comparison to a lot of the rest of Europe. What would it take to change this? One possible scenario that I've flirted with is avoiding the 1940 Fall of France but still having the Soviet Union conquer the Baltic countries. Then, in the 1980s, due to the 1910s-1920s male cohorts not being decimated by World War II (at least not anywhere near as much as in real life, and possibly not at all depending on events), someone other than Gorbachev comes to power in the Soviet Union and turns the entire Baltic region into a special economic zone along the lines of China's Shenzhen, which saw its population absolutely explode during the last half a century. Anyway, does this sound realistic enough? Without World War II's extremely demographic devastation, the East Slavic lands should also have many more people to spare, which in turn also means them having many more people to export to other SSRs.
The Baltic region simply doesn't have all that many people nowadays, with the exception of a few major cities. Certainly not in comparison to a lot of the rest of Europe. What would it take to change this? One possible scenario that I've flirted with is avoiding the 1940 Fall of France but still having the Soviet Union conquer the Baltic countries. Then, in the 1980s, due to the 1910s-1920s male cohorts not being decimated by World War II (at least not anywhere near as much as in real life, and possibly not at all depending on events), someone other than Gorbachev comes to power in the Soviet Union and turns the entire Baltic region into a special economic zone along the lines of China's Shenzhen, which saw its population absolutely explode during the last half a century. Anyway, does this sound realistic enough? Without World War II's extremely demographic devastation, the East Slavic lands should also have many more people to spare, which in turn also means them having many more people to export to other SSRs.