RTF is a global modification that replaces all towns in the game.

I think with this setup, NPCs will never come to attack you, so you'll need to significantly increase their intelligence.

On what basis did you form this opinion? How do you know how NPCs think? The only way to find out is to test it.

Added 1 minute ago

1 champion doesn't seem right with this system....

Dyrman said that this can be implemented and, moreover, has already been implemented, but he didn't say how or where!