Well, just random land raids would be nice even if there will be hordes of enemy troops, because you don't have to kill everyone, just grab some loot and run. Pirate ships is stealthy for a reason, right?
And there must be a time window, like main forces left the base and you have to raid it before they come back. Raiding same place again and again is very exploitable. You might need some new artwork and maps though
And yeah, i think i'll suggest a mobile base concept for engine development. Who knows, maybe someone find this idea appealing.
Actually your mod is awesome. It actually feels like a new game, not just adding a couple of new things or making play more difficult. Loot-oriented supply is fun too, like you can arm your girls right on a battlefield, and let the enemy taste their own plasma