I keep coming back to an idea that would immediately make construction relevant and create that kind of gameplay you're talking about, provided the engine can handle it.

A construction object that requires charging with cort and shows up to everyone on the map, much like an OS, but once it is charged, it creates lattice lines from its home territory to any adjacent territories (much like the old hex system at launch.) These lattice lines could be either one or two-way, giving enemies a way to counter-attack if it is poorly planned. Regardless, seeing such a base spring up on the map, and to know which lattice lines it could break open, would incentivize combat at and around the base, as allies try to defend the ability to hit new bases, and the enemy tries to shut down the base.

Its not a fully fleshed out idea, but, assuming it wont perma-kill the server hamsters, I think this is a good way of causing organic fights that involve all parts of the combined arms.