I made an Argus cry "mommy" with my Scorpion while it, nine fighters, and a Hydra were beating on me and my two wingmates (a Scorpion and a fighter). We all died, of course, and they took no casualties, but I did make it cry uncle even before the other Scorpion went down.
This, however, is hardly indicative of the usual, or of overall balance. I have a particular aptitude for dealing with things larger than myself regardless of what specific ships are involved (in a Bundschuh Odin, I once got a Das Wilde Rheinland Gunboat to flee). The Argus captain in question wasn't terribly combat aware either. While your experiences may be indicative of the "problem" (quotes used for skepticism) the fact that a cap V Tridente cannot solo a destroyer explicitly designed to destroy gunboats hardly strikes me as an argument for resizing it.
The problem, if there is one, is that as the Kusari Destroyer is balanced toward fighting smaller craft (gunboats, even snubcraft to an extent) the logical counter would be a larger cruiser. The BAF can easily deal with that, as we've established. However, the Kusari revolutionary forces... can't. This is why my previous suggestion was "fix the Kagutsuchi, then figure out what needs to happen with the Kusari Destroyer". I stand by that suggestion.
To address Freestalker, yes, brilliant idea, let's go to a completely separate balancing concept after spending months revising things for 4.86. It might actually be ready by the end of May or so, but not if we do another overhaul. It's also a pretty silly idea to separate things that close together in size.