the hengeyokai crew doesn't have to be cats, since there are lots of hengeyokai flavors.
you could have a ship crewed by several hundred sparrow hengeyokai monks who spend most of their time in bird form just sitting on the rigging and chirping at each other.
in a boarding action this force is very powerful, since they can fly over the other ship, transform into humanoid form midair and start dive-kicking the crew on the other ship's deck.