Roguevictory wrote:I knew about them filling a role like that of the light cruiser though I thought they were all retired by 1900 PD and had been falling into disfavor since Roger III started focusing on building a navy to fight a war with Haven rather then one geared for anti-pirate missions. My mistake.
Actually, mine. I (mis)spoke without looking at my ship database. There were still some RMN frigates in mothballs in 1900 PD, but none in active service.
Roguevictory wrote:I knew the original Manticoran Victory class Frigates were almost certainly retired by A Call to Arms but I thought there would have been more modern frigates in the RMN at the time.
It would still be surprising IMO if the Volsung didn't have any since IMO the long legs of the class would be very attractive to buyers for a mercenary fleet at the time though I'm not certain if every ship in their fleet was in A Call to Arms or if all the ones there had their type identified
Largely it's a matter of definition. The same basic ship class, with a slight emphasis on cruising range versus armament can be called a frigate or destroyer by different navies. There is a lot more blurring of the lines between classes in this era, especially given the rapid technological changes of the 16 and 17th centuries. It's not quite as simple as saying that if it's in this tonnage range it's a frigate while this tonnage range is a destroyer.
By the mid 1600s PD you'll start to see a lot more commonality between different ship types, their roles and their tonnages. But at this point it's not at all uncommon to see a Frigate in one navy outweigh (and even outfight) a destroyer or light cruiser in another.
Specific to your points above, the Volsungs actual mission role and how they operate strategically and logistically gives them far fewer uses for a frigate (by which I mean "lightly armed, long legs") than one might assume. You'll see more about this in later books, but their particular operating patterns are closer to those of a pirate gang than a regular navy, or even one of the accepted, bonded "Contingency Management Firms" like the one run by Gustav Anderman before he retired.