These thoughts are more speculative, but prehaps somebody can shed some light on them. That is if anybody reads this blog. :-)
Russian-Germans in South America
By WWI there were about 250,000 Russian-Germans in Brazil compared to about 150,000 in Argentina. Yet the literature on Russian-Germans in Argentina is much much greater than on those in Brazil. My LOC subject search came up with one book in Portuguese on Russian-Germans in Brazil. But, it was only published in 1997. There were over a dozen books on Russian-Germans in Argentina. Why this discrepency?
Russian-Germans in Azerbaijan
My reading suggests that the Russian-German communities in Azerbaijan may have fared among the best of the settlements during the 1920s. It also suggests that this was due to two factors. First, the Azerbaijanis unlike the Russians and to a lesser extent the Ukrainians had no anti-German prejudices. Hence they allowed more real autonomy for the "Konkordiia" villages that formed its German national autonomous raion. Second, the highly religious Russian-Germans benefitted from living in a predominantly Muslim area. The assault on religion in Islamic areas of the USSR did not begin until 1928, several years after its initiation in Christian majority areas. They could thus maintain their religious life to a much better extent than Russian-Germans in places like Ukraine and Siberia. This is just a preliminary conclusion, but it seems logical.
This going to conclude my short series on Russian-Germans for now. I will undoubtedly return to the subject in the future. Especially, if I have any requests. I might also cover other ethnic groups in a similar manner.