I think all Outcasts and their leaders especially should decide on what OCies should fly. If you think the destroyer is too light, try any other cruiser in game and you will realise what is better.
Variation in ships... Allright, but first get 2 months to learn system modding, make 3 new systems for Outcasts, where the new ships can be sold. Then get 2 months to make the ships yourself. Then trade 2 months to buy those new capships you are pleased with and in the end simply spam Alpha and nearby systems with capships.
Why dont you want a nice LF? Or a decent HF? And who are you to decide for all Outcasts?
For the ships: Outcasts have two battleships. Only they, Liberty and CR have two types of battleships. (Osiris is Order)
Outcasts have a strong and nice destroyer with 12(!!!) turrets. And they are going to get a GB soon. (More people are willing to make it.)
Also, Outcasts have many allies with very nice ships. I dont mean Outcast should buy a RH or LH ship, but Being a LH still means you are on the OC side.
The dessie doesnt fit the line, thats true, but I believe a little retexturing and woila!