A New Dawn Stories: From last to first

I'm not sure if you mentioned this, I looked around but didn't see: what version of AND are you using? Because I'm pretty sure I have the latest one and it doesn't have a lot of the options that you seem to have, like the ability to switch nations at will, et cetera. Or do you have an older version?

You can switch nations in any game, using any mod, so long as world-builder works. The steps to change nations are as follows:

Step 1: Open World-builder
Step 2: Without changing anything, save the worldbuilder map as a scenario
Step 3: Open the scenario you just saved. You can select any nation that is currently alive, and also you can change the difficulty level (I think)

Hope that helps!