{Larger Sail for Galleon}
as you can see from the picture those sail looks different depend on class of ship (Left is 1st rate Galleon in a middle and right is brigantine )
or
just make the galleon smaller whit a lot of gun ports to make them looks different from the brigantine.(Galleon right now looks totally 2rd-rate)
{More Sail}
i think you should have added gaff sail and jib sail that will affect the ship turn rate