

The naming convention is vague.
LD’s California class is a dig at what the writers perceive as shit or boringly average California cities nobody knows if you don’t live there.
DS9 had some consistency with naming all runabouts after earth rivers.
All other names are up to the writers. So you get a Crazy Horse next to a Shenzhou, a Hood next to a Defiant.
Canon probably runs along the Memory Alpha/Beta divide.









It’s all based on navies here on Earth. They chose the language to make certain ships this-or-that class. There are no definitive rules so far as I’m aware. A certain class of submarines would be designated something class because they shared the same weapons or the same propulsion system. So when sci-fi writers picked up this ball they played fast and loose with already fast and loose rules.
You may need to clarify what you mean by canon in this context exactly. If this Walker class appeared in a live action TV show I would say it’s canon. If it’s in a novel or an animated show I’d say it’s not or not necessarily. Trekkies can spend weeks debating this sort of thing.