P.S. Let's define ship roles more clearly. See my subjective number suggestions for the Mobula and other ships here:
Nerfing the signature strength of the mobula (vertical lift) would do the opposite of defining ship roles more clearly.
If we want more defined ship roles, then gaps in other forms of manuverability/mass/armor values would need to be expanded to match the current strength of the mobula.
Think about the following:
Mobula - Kept roughly the same. Reduced hull permahealth (to reward hitting the hull at long range, and punish mobulas that get into brawls/get rammed)
Spire - Boosted armor, dramatic turning acceleration buff. (Turns spires into fantastic close-range turrets)
Squid - Bring squid permahealth down and acceleration/speed up, closer to release squid. (Uncatchable, fragile speedster/flanker)
Pyra - Dramatic forward acceleration, slightly boosted armor, turning and vertical acceleration even worse than current. (The pyra excels at spearing/charging enemies, but needs to plan ahead to get that ram)
Junker - Mostly unchanged. (Junker manuverability is in a good place for their role)
Goldfish - Mostly Unchanged. (Goldfish manuverability is in a good place for their role)
Galleon - Mostly unchanged. Further top speed increase, acceleration remains very poor. (The Galleon would be the fastest, heaviest ship, but the absolute slowest to get there. Anyone unfortunate enough to be rammed by a galleon should be in for a world of hurt.)
This would solidify each ship in a specific role by giving them one or two things they excel at (minus the goldfish and junker... which are both jack of all trades ships by design), and would give most ships maps/areas where they can excel.