OK, well I finally got my ass into gear and here are the results. Note that my formula for dumbing down ship stats favours firepower and armour, as it was designed to simulate fleet actions, where vessels have to close and engage, so fast designs, not set up for fleet actions tend to be heavily penalized.
That left the rankings as follows:
1 Defender (ATN082268)
2 Apollo (Able)
3 Blacknova (Masterarminas)
4 Resolute (Irose)
5 Alisha (Drakensis)
6 Nova (Takiro)
From a battle line viewpoint, the Defender is the go to, but it is more of a small cruiser than a destroyer. The Apollo was the best balanced design, with the Blacknova, Resolute and Alisha all fairly similar in overall capability, with all four being good Destroyers in differing roles. The Nova, though fast and a true picket, was panned by the conversion.
Based on what I can buy for a set budget and what that gives me in flexibility and firepower over the number of hulls of each class I could buy, they rank:
Apollo (Able)
Aliesha (Drakensis)
Blacknova (Masterarminas)
Defender (ATN082268)
Nova (Takiro)
Resolute (Irose)
So although the Defender is a brute, it is bloody expensive, where as the cheaper Apollo, Aliesha and Blacknova can get me more hulls doing more damage total. the number of Nova's makes them a possible buy based on hull numbers and the Resolute, due to lack of power and highish cost bottoms out.
However, when cost is compared to firepower for series production, the following applies:
Resolute (Irose)
Blacknova (Masterarminas)
Nova (Takiro)
Aliesha (Drakensis)
Apollo (Able)
Defender (ATN082268)
The Resolute's in a group production run will hang with you through numbers and hull strength, with the Blacknova and Nova not far off.
For series production on an all rounder, go for, surprisingly, the Nova. It is cheap, but has enough all round capability to make series production a real option and with that many fast ships all over the shop, it would cause trouble.
Nova (Takiro)
Aliesha (Drakensis)
Apollo (Able)
Blacknova (Masterarminas)
Resolute (Irose)
Defender (ATN082268)
So, if you want a one off brusier, you cant go past the Defender for one on one action or close fleet escort. For series production for a attack vessel, you want the Apollo, and for series on a defensive vessel, go for the Resolute. The Nova is your go to for general series production, either that or my sums are broken as it's an odd bird.