I checked the Shipyard and noticed not ALL the Fleet Ships take Modules, some take JUST Fleet Credits (Rather high numbers of them too, 20k and up).
Of course they're not as good as the ones that take modules though.
the problem is, those ships suck big time. even the fleet versions of those ships are bad (at best).
these are too expensive, and really hard to get. if we have a starbase with military tier 5 (which we will work for a year or more), at least dont make us pay for the damned ships. or make them more accessible, if they are so expensive. this way we can only lose