Your best remaining city spots are Fall, Orcish, Brian, Aular, Ubic, and Arran. That gets you to 8. After all those are in, and you are ready to pick a fight add the final 2 cities at Yuntin and Xiji. 10 Total Cities, 24 Spire Shipyards is 3 dreadnaughts, 6 Battleships. For the final chapter you have 3 major defense points at Xiji, Yuntin & Arran, with fallback defense positions at Murdoch and Yoda.
You also have the option to take everything on the Arran wing and defend at 2 points.