If Genesis 10 was written and/or edited during the Babylonian exile, it should be understood a reminder. Everyone who read it would have looked back to how God weaved history to bring us to the present.
The text suggests God doesn't merely follow individual lives, but also Nations.
This isn't some new revelation. It's just that "nations" and "kingdoms" are statements about human achievement. They're the largest things humans can construct. The only thing bigger than a kingdom is a bigger kingdom.
And as the text goes on, nations and kingdoms become a central theme in Scripture.