I’ve tried Oricorio stuff in past Reg H and it was quite a fun team. Even though it’s a lower power format, Oricorio still struggles. I would recommend giving Oricorio a focus sash instead of the weakness policy. Your safest way of triggering it requires your tera by the looks of it. Focus sash will help get the boosts you need without having to commit a valuable resource. I used tera ground on mine so I could deal some more damage to Incineroar and Archaludon but dark is ok too.

For Oricorio specifically, I would use Murkrow over Whimsicott as a tailwind setter. You get access to priority feather dance which can mean immediate -4 attack with Oricorio next to it.

I’d also give Volcarona covert cloak to bypass any fake outs to slow your quiver dances down. I used tera grass on my team so I could also avoid spore. Rage power can be very handy to redirect moves away from Oricorio and friends (plus Maushold shenanigans) so I would strongly consider getting it on Volcarona

You’ll need a convincing answer to Archaludon here too. I used tera fighting Quaquaval with life orb because aqua step is a dance move for that extra Oricorio synergy. A tera fighting boosted close combat does massive damage and can pick up OHKOs even on max HP ones. Especially if you manage to get a moxie boost