Just spit balling here...each CG tier could be a station saved/evacuated. Save 5 stations, hit tier 5. Save 50% of people from each station then tier 2.5 reached.
Ok I play.
Say FD keeps on bringing on goid attacks after goid attacks, while turning them increasingly more difficult, at one point there could be more systems than AX-players could defend and amount of CG´s would just increase every week, until board is 100+ CG´s long. Then what?
I´d rather take good alien invasion any day, rather than new kind of CG, tbh lol