If memory serves, the manual suggests that the TEC warships, including all the capital ships but the Marza, are primarily reconfigured civilian designs.
In-game, the icons for these ships tend to be far larger than the freighters zipping between refineries, extractors, and trade ports. This suggests that either
(1) the redesign process involves massive inflation,
(2) the ships *are* larger and the backstory is fluff that wasn't written to imply anything about the game, or
(3) the /icons/ might be large, but they bear no relationship to the actual size of the ships but instead reflect their relative importance; and that the warships may in fact be very similar to civvie ships (with the possible exception fo the completely new designs).
Case (3) would be intriguing, in so far as there are certain sorts of missions you might give to the more experienced crews regarding camoflague -- having actual warships somewhat modified and probably with temporarily powered-down scanning / weapons systems (or some other way to bring heat/radiation signatures to look 'normal'), in order to be considered lower-priority targets and perhaps better able to ambush. You wouldn't expect a novice crew to pull it off, 'tho -- novices not have the full breadth of experience that tells 'im how to distinguish between a warship and something else (consider that in the Ubiquituous Laser Age, relying on approaching to easy visual confirmation range would might easily you killed), and also might lose their nerve and either not trigger at all or reveal themselves too early.
That does touch on the concept that if there ever were to be a decent fog-of-war or a revised experience model, it would probably be more realistic for experienced crews to be better at identifying / spotting contacts, at coordinating fleets (more sensors better coordinated => better tracking of contacts, for better targeting or avoidance), more efficient at damage control, more competent /confident at knowing what safety margins can be exceeded when (e.g. overloading propulsion systems, or zooming a bit closer to a star than 'textbook recommendation' -- express as percentage bonuses).
