There are more players too I could name. Corne Krige for example not born in SA. How many more examples before you concede that your "rule" actually isn't one and in many of these cases the rationale for moving countries (better life etc) is exactly the same rationale put forward for people moving to play rugby in other tier 1 countries?
Ok, but you realise you have nothing to back that up with? What you've provided is a blind assertion that is not demonstrable, and I would suggest is a "stretch".
To demonstrate this stretch, I look at a more "professional" sport in one of your examples, namely football in Russia. You'll note in recent years the increasing number of players born in Brazil who are representing Russia at football. This suggests that a nation like Russia, when they can offer a quality of life package to people from poorer countries, will do so.
Thanks for playing hbijbjon