Also I'm working on this matter and I did the following tests in some swiss clubs which represent strangers communities, f.i. FC Kosova Zurich (team formed quite totally by kosovar or albanian players).
To make this test I forced game to fill missing players in available teams, so it created random young and older players without waiting the creation of young regens in the club. These are the results:
1) I kept the nation and continental cup nation in Switzerland, and change the based nation in Albania: all staff was albanian (good) while players were quite totally swiss with swiss names and the worst result was that all players seemed to play in Albania because in every personal details tab appeared the number of days in this country (Albania!!!) before getting the 2nd nationailty. It's weird because swiss players playing in Switzerland could get albanian nationality... Bad.
2) I kept the nation, based in nation and continental cup nation in Switzerland, then I duplicated base city (Zurich), creating a sort of city quarter (Zurich qt. Kosovo), keeping swiss nationality but changing population (10% of total according to real stats about immigration in Switzerland) and changing the spoken language (albanian): I had a good result because staff and many players were only swiss, some players were swiss/albanian but all of them had realistic albanian mixed names and speaking albanian language together with german or french (swiss main languages). Good.
3) I tried the 2nd test changing the nationality of the duplicated city (set in Albania) but keeping it in a swiss region: result wasn't good and totally unrealistic because all players and staff were only albanian! Too Bad!
I didn't edit stadium place in any test.
In my opinion the 2nd test is the best even if not perfect. Hope it can help .