Again I personally don't want to limit anything for anybody else but a capship only option would be nice.
I've been playing a custom map with plenty of ressources for everyone and for me being able to build and turtle a bit (just vs AI). The map is 2v2v2 and gives a planet of each type for everyone. Only access to each other is through a pirate base and then central star.
I was slowly nudging my way to the enemies clearing out the piratebases when I discovered the AI hadn't been idle at all. Their combined fleets consisted of multiple ship types with the most being eg. javelins with around 70 plus. I'd say they have around 300 ships at the planets.
My counter being titan, capships and then with a massive escort carrier fleet of 70 plus. And the deviousness of asking my own ai ally to attack first lol. Anyways the game is winnable but it sure does become slow. I'd wager aroudn 3-5 frames per second. Though thats with the rather elderly system of an e6500, 4gb ram, gtx260 and running at 1920x1200 and decent settings.
So an option small fleets of big ships would imho have an extra benefit.
It would allow for rather big maps and long games and still alllow for better performance.
EDIT: Also atleast in my humble oppinion a "scarily huge friggin" fleet should obviously stomp a starbase and pretty much anything in short order (since it's friggin huge and scary). Unless we call it a deathstar but then we need a trenchrun ability for fighters.