Countries With the Most NBA Players

I presume you got the data on height from wikipedia, which is very poor (Bosnia is basically male students in one university, which obviously is extremely flawed). Going by a study published in eLife in 2016 (10.7554/eLife.13410), there's not much difference between northwestern Europe, the Baltics and former Yugoslavia. Only the freakishly tall Dutch stand out. I'd say interest in the sport is at least as important as average height.

Yugoslavia was not in the Soviet sphere of influence since the The Tito–Stalin Split in 1948.

Yugoslavs (especially from the southern mountainous regions) are basically the black people of the white race, athletically speaking (although I realize there are differences between different ethnic groups of black people in that regard too). It's not easy being a scrawny man in such a country. You're not exactly any woman's first pick (speaking from personal experience). I reckon I'd be an average human in most other (non-African) countries or a giant in Asian ones :)

Basketball is so popular here in China, but they suck pretty badly at all team sports. Still pretty surprised that they didn't even manage to make the list though.

Yao, Yi, and ... ?

Is Greece not here because 4 of them weren't born in Greece? I think Greece should be included because it should be by what country does the player represent.