Would be interesting if the "final boss" of Act 3 would be the Proselyte. Basically, you'd have to defeat yourself.
Would be also interesting if it was like RA Allied Mission 2 and 4, in one mission you build up your base, and in the other, you have to destroy the same base.
I'm kinda guessing if how Act 3 would play out gameplay wise. I think it could work if instead of Foehn Only, there would be a sort of switch between the two factions; one mission Foehn, then next mission Epsilon, and then a final mission which would be Foehn. OR, the final mission would have two versions: One where you bring Foehn to victory while the other, you control the Epsilon, and you decide the end of the story.
Actually, I wonder if there's a way to branch missions. Like what you do in the penultimate mission will lead to you either bringing the Foehn or the Epsilon to victory in the final mission.