Some nations have much less good managers then others. I switched to some random nation and I was first in the nation, while barely being in the top 500 worldwide.
But when I switch back to my original nation, I'm only 23rd.
Since it currently only costs 5 tokens to change nation, it would be easy to cheat out of money by switching to a nation not many have heard of. It would also give an advantage to people in small countries like this assuming competitive people don't switch to their nation.