Russia's attractivity to foreign workers depends the availability of convertible money (sending money out of Russia is currently probably a bit of a problem and will stay so for a long time) and their security (which is probably not a given, with the rise of fascist state the security of foreign workers will not be the highest item on the list). So while everyone likes oil money, not many people will be likely to immigrate to Russia for that.
2/3 of world's population won't have any issue converting currency to yuan if BRICS decide to use it for mutual commerce (though I doubt a WW3 won't happen before this happens).
