Currently this is just an idea, but I am toying with tying titan production to very high levels of a certain capital ship, instead of making it a standard building procedure.
you know, i agree with Jarquafelmu above. in many smaller, faster games i don't ususally get my capital ships all too high in level.
In long, epic battles, however, this mechanic would be necessesary in order to stop people from gathering huge resources and building a load of them before any combat at all. I would hate to meet up with my enemy for the first time and be butchered by 5 titans and a couple frigates. That would be a pointless game. it would turn into a race to see who could build the most titan class ships.
maybe a ship that is specialized in bombarding titans is in order. that would balance things out a bit, i think. maybe a special squadron of fighters that launch and start popping holes into the nearest titan to protect a fleet, because from the sounds of it, these titans will be able to truly take on an entire fleet of 30 ships and put up a hell of a fight, even if it loses.
although, overall, i like the idea of having to earn your titans. they would truly have to be pretty damn powerful though.