As far as the narrative track is concerned, I think we should import Adam Harry's concept. I loved that apoc style game we played at BFG.

One smaller game played by Frank and I. We had a grid of the big Apoc table and at the end of every one of our turns, whoever controlled the objective fired a big apoc template at a grid coordinate on the big table. LAZORS FROM SPACE!!!!

We can expand this to 2 tables or more and these are the ships in space with boarding parties on each one. From here, the boarding parties are trying to wrest control of the enemy ship and vice versa to fire on the surface.

You can also expand from here with things like, whoever controls the lander ship gets to deploy first on the apoc table or who gets to deploy thier titans first.

I love the idea of the smaller tables affecting the bigger tables.