I just played a game as the arceans and decided to build a military strategy based on fleet modules. (difficulty crippling).
I started by rersearching strait to basic logistic and weapons techs. (no defence no hull techs) I build (rush buy) a cargo hulls with a command center, a speed bonus center and senors strait after i researched the first level of logistics. You can then accelerate your colonny rush and use it to grab resources faster with a constructor. After that by putting the command center ship with a fleet of small ships with only weapons i made two big fleetss that where basically unstopable. With the speed bonus i was able to always atack first and with the arcean first strike the ai never got an opportunity to fire back.
I was behind the ai technologically but by using fleet modules with bigger fleets of smaller ships there was nothing the ai could do to stop my fleets except use those modules as well which it never did.

I don't know if it is intentionnal or not to have the command center and warp bubble strait from the start (don't think so since there are specific techs in the tech tree that have the same name as the modules) but anyway the ai should use fleet modules much more. A cargo hull with two fleet modules and sensors costs nearly nothing (200 bc same price as a small warship) with the second level of logistics you have 17 logistics points so one command center + 4 small ships has the same firepower and cost as 5 small ships but you get an extra +3 speed and extra sensors free. anyway i guess the ai should focus more on logistics and on building command centers than it is doing now. (especially the drengin with their supper corvettes). The first level of logistics allows you to group a colony ship or a constructor with a command center. I managed to research the logistic tech before the colony rush was over and it was nearly an unfair advantage over the ai. The second level makes a command center in a fleet more cost efficient than an additional ship.