Sounds interesting, but I think it would give an unfair advantage to bigger countries like Spain, the US, Italy, ...
But at the same time, you would have Spanish players who are not good enough to be on the Spanish NT, who would start playing for Barbados.
I'm don't think it's a good idea, though.
"Air is beautiful, yet you cannot see it. It's soft, yet you cannot touch it. Air is a little like my brain." - Jean-Claude Van Damme