: The problem with that is that the UNSC obviously still uses the same
: conventional nomenclature as current navies do today, and the UNSC Navy
: are apparently the ones that gave them these designations. All the UNSC
: ships appear to fit this system. We have the small frigates, the
: similarly-sized but more powerful and heavily armored destroyers, the
: large and powerful cruisers, and a "light battleship" that's
: despite having a similar overall length to the typical UNSC cruiser is
: likely far more massive, heavily armored, and packing more firepower (some
: of the smaller battleships of the U.S. Navy were similar in length to the
: average cruiser, but with more armor and thus greater displacement, and
: bigger guns to boot). Similarly, the Covenant has the larger CCS- and
: RCS-class cruisers and the much smaller SDV-class corvette. The itty bitty
: CRS-class (smaller than even a UNSC frigate) is when put in relation to
: other Covie vessels little more than a patrol vessel.

We have this because at a time when it wasn't that apparent/common to know how large objects were in the Halo universe, a mention was made of a 300m long cruiser in a novel. So that's why we're jumping through hoops trying to justify the design.