Light destroyers good reconnaissance missions. What do they do in battle with a lot of medium and heavy vehicles?They are, but they can't operate on their own. To deploy the gunboats you'd need a light cruiser or other ship with tow points. So a light destroyer group would be useful for recon or other missions where deployment in force is not required.
Light destroyers durable heavy gunboats, but not twice.Light destroyers are also more durable than heavy gunboats, and can be equipped with bolt-on torpedo racks.
Efficiency torpedoes low.
Light Destroyer should bear FTL drive system and interstellar navigation. This increases their price. And reduces the volume and weight for useful systems onboard.
For scoutship rationally. But it is not rational to send the ships in the battle, when medium and heavy vehicles a lot, and they can bring the sub-ships.
Why light destroyers may not be the same sub-ships as gunboats? Why do they have with their own ships FTL drive?
The difficulty of combining different systems in the vehicle - it is not logic, but the physics. This means that Umiak spend on the development of projects of ships and weapons systems greater intellectual resources than Loroi.Perhaps, but perhaps not. We don't know if those same design principles would apply to building starships, or to an alien's logic. Either way it's obviously seemed to work for the Umiak so far, considering how many ships they have.