I haven't even read the whole thing, and here's my biggest gripe:
You give guidlines on the numbers that entail a class.
This eliminates a great amount of freedom in ship creation, (unless you use CLS-186.5 or some other ungodly number).
That said, it would however, be a good way to denote prototypes and possibly civilian craft with a little tinkering. Although civilians shouldn't be able to get their hands on destroyer class vessels (legally anyway).....
*Now I have read the whole thing*
As far as the FS ship arrangement goes, Perhaps on the conception of a Space fleet, they just said "What the hell, I want a destroyer to be larger than a cruiser."
We are talking about Command here, who aren't exactly known for their brilliant mental capacities.
*cough, cough, "Sir, we have hull breaches on 12 decks! Half our crew is dead!"
"Phoenecia, remain on station", cough, cough*
