Named for famous ships.It's not like every class of starship has a theme unifying all its names. What possible theme could there be unifying Galaxy, Enterprise, Yamato, and Odyssey?
That only applies to two of them. The Galaxy class was named for the astronomical object, like the Constellation, Nova, and Nebula classes. And Odyssey is the name of a work of literature, analogously to how the Miranda class is named for a Shakespearean character.