Hmm, I'm not sure. I'd probably keep the people on the same countries, since I want to have Kiro fight the five mechs again. However, the next few missions will be much much harder due to the CB pulling the strings. Expect a lot of unexpected developments made to look like a stroke of luck.
As for the next chapter, how about trying to take down the Coalition of Sigma? Once you get close enough to the capital, the CB will pull the plug and take it over, causing the Brotherhood to be pushed back. Let me put it this way, their military consists of mechs that are even more advanced than the ones you just used to attack the Coalition, only with less experienced pilots. Hey, when you have a shadowy organization, you don't have a lot of room to train without causing suspicion.