How much stronger are fishmen in the water, really? How are they stronger?

[Warmmedown]

On the raw strength/endurance side, are they just comparatively stronger, because humans get weaker in the water?
Is the only boost from the access to additional techniques, like the water bullets, and not from any strength boost? Or do they actually get more muscular strength or more endurance in the seawater?

Also are they stronger in seawater than in non-sea water?

 

[Yoshi]

They’re probably just literally more adapt to fighting underwater. I don’t think it’s anymore complicated than that.