greetings. I'm a very active editor and I discovered something that I haven't seen discussed on the forum yet (although I believe some already know.
creating cities in the same coordinate, but with a foreign local region, increases the chance of the club receiving a newgen with dual citizenship. if you use the original cities in the game (which have low unique id) it seems to work 100%, with created cities it partially works.
*in this case, I created a club in a city that has a lot of Germans, Poles and Austrians, if it was for just one nationality, it was obviously simpler to just move the club to a local region of that country.