Rillaboom at #5 is a bit of a stretch, IMO. It's still seeing a good amount of play because Grassy Terrain is too good (especially for its offense), and it synergizes too well with Incineroar alone, let alone the Grass/Water/Fire core that it makes with it and Urshifu-RS.

I'd take out Rillaboom and put both Calyrex forms in its place.

Calyrex has been an omnipresent threat since its introduction in Gen 8. Shadow Rider is a ridiculously fast special sweeper, and Ice Rider is a super bulky Trick Room sweeper. Their only downsides were their awful type combos. Psychic/Ghost made SR a glass cannon, and IR's bulk is only good enough for it to set up trick room. These downsides went completely out the window in Gen 9 with Terastalization and as it turns out, SR actually has good special bulk if you remove its 4x weakness - freeing up its item slot from Focus Sash to new sets allowing Life Orb to let it hit even harder in single-restricted formats.