Here's how I see.
Cutter-end game trade ship capable of standing against pirates should it come under attack. A bulk trader designed specifically for sex appeal with its nice curves and delivering the most luxurious slaves in the most luscious style. It demonstrates the empires commercial prowess and cultural might. (I'd like to state I am an outsider in imperial rank)
Anaconda-a commercial corvette class vessel designed to give options for both firepower and trading ability. A merchant marine if you will, something that's not as effective as a t-9 but a higher survivabiliity.
Corvette-combat.... Simple as that. Raw firepower in the form of twin huges and excellent staying power. Needs to be towed into firing position by its big brother the Farragut who can then go play with the big boys while junior takes care of pirates. Could theoretically work as a short range trader but seems a waste of its potential.
I only own the conda but this is the impression I gain from these ships. And I like that the corvette and the cutter are mostly one sided in their intentions but both are reasonably able to do both.
Instead of an actual ship buff the new equipment should help determine the ship roles.