Ok so I looked up what Serebii was and besides being Celebis Japanese name, I got no idea how to navigate that site to find the categories but I'll trust you on this.
I also knew that they were going together, but I think having all the subs and myths (minus Arceus) in part 1 is a somewhat unbalanced split, 7 to 4 compared to 6 to 5. if you expand that split to encompass that actual Pokémon involved its 9-4 but thats less important. Perhaps I'm just underestimating the ship scenes and at the end its your call.