So, what do we whitefellas do who've arrived in SAf/Aus/NZ over the last few hundred years? The history of mankind is one of perpetual movement around the globe ever since we could stand up and walk. Indigenous people born in Tierra del Fuego are direct descendants from those who trekked over the then-connected Bering Strait tens of thousands ago.
I often, mischievously, ask for a Welcome to Country from our Pommy friends. There've been migrations/invasions from Angles, Jutes, Saxons, Picts, Celts, Romans, Vikings and Normans in the last 20,000 years; HTF does one cobble together a WtC from that lot? The history of mankind on this globe is one of perpetual movement, which is why we should always be receptive to new visitors. Those who say one bit of dirt belongs to their lot over others because it was given to some ancestor thousands of years ago aren't being realistic, or, if I'm being brutal, honest. For example, look at the current shitfight in the Middle East: both Jews and Palestinians both have equally valid claims over lands in Israel. I think I'd better stop here before things go apeshit.
Rugby players are no different to wandering Neanderthals, they go to where they think things might be better. Point: how many SAf/Aus/NZ test players are sons of British and Irish parents? I rest my case.