>His staff literally were absorbed into the Russian sand US space programs.

Not really in case of the USSR. German group in Russia was isolated and Korolev didn't like competition. Soviet space program started by replicating German rocket, but once all production chains were created, it was off on its own course.

I highly recommend English translation of memoirs of Boris Chertok[0] to anyone interested in the history of Soviet space program.

[0] https://www.nasa.gov/history/history-publications-and-resour...