such differences mostly come through the training philosophie, and you also had this in Buzzerbeater because national communities often had a little bit different philosophies. For example the italian community, didn't train much one on one for a long time on the guards. Maybe country X value high more in Big men so that more 7ft+ guys get trained(mostly those with low starting skills), and other communities go a lot more for multi skill etc.
And that also the reason why your prejudgices are partially right(i really don't like the chinese one), because the basketball school in baltikum and yugoslawia rate fundamentals and tactics higher then the american one who work great in the athletical department. Which leads in the end to different player types, even when the player looks from the start one quite similiar.