In terms of general usefulness when creating a 2v2 team, since that's the game mode most people play on this game:
1. Pyramidion
2. Junker
3. Galleon
4. Mobula - Goldfish
5. Squid
6. Spire
The Pyramidion is first solely because it's paired with everything very easily. It's a solid ship with it's ups and downs, but generaly very useful since it can give chace. It can easily pair Piercing + Explosive.
The Junker is the best overall ship in the game currently so it is imperative that it comes second. It requires a bit more game knowledge to run it properly. It can easily pair Piercing + Explosive, while also bringing supporting disablers as an added benefit if the pilot desires so.
The Galleon is a formidable ship when ran by an experienced team, but doesn't stick with everything and requires careful planning, also requires a good tackler ally and is generaly very hard to run.
The Mobula and the Goldfish are probably equally powerful at the moment, while I personaly believe that the Mobula's horrible handling and horrible deck layout makes it less desirable, the Goldfish still has the glaringly obvious weakness of its exposed front gun being easily disabled, other than that, both ships are pretty equally useful but require to be paired with an appropriate tackler ally. Also Mobula might be getting a bit of an edge because of the ability to use Piercing + Explosive as well, but it's pretty offset by very weak stats and carronade bait balloon.
The Squid is a ship that lacks a lot of firepower to be considered a battleship, it only fills the niche role of disabling slower ships and taking advantage of their blindspots, but any Junker will completely trash it since it practicaly has no blind spot except above its balloon, where the Squid can't return fire anyway. A Pyramidion can also take care of it pretty quickly as well and Goldfish can utterly disable it by either equiping a carronade or a Hwacha, turning it into a sitting duck (no pun intended about the actual clan). Since it doesn't pose nearly as much threat as its ally, it will probably be ignored and its ally will be focused down pretty fast, leaving it alone and unable to do anything.
The Spire is a slow Goldfish, with an even more easily disabled front gun and very weak stats. It never actually manages to work with a trifecta since even if you take the slightest bit of return fire your engineers will be scrambling to keep this piece of metal alive, hence the firepower of the Spire can't be used all that well, it is also very easily focused and brought down, faster than most ships, hence it wins the 'trash tier' award.