Not sure if I'll make this an answer since I haven't used Poison much in NatDex Monotype, but there are a couple things I see that I'm going to address:
- You don't have a Ground immunity on the team. You could replace Fezandipiti with a Ground immunity, preferably Crobat since it can check Mega Gallade.
- You don't really need Glimmora in NatDex Monotype. You could replace it with Mega Venusuar since it can check Electric- and Ground-types.
- Toxapex needs Scald, so use Scald > Baneful Bunker. You can replace Knock Off with Toxic.
- You shouldn't have Okidogi and Sneasler on the same team. I'd replace Okidogi with Alolan Muk for a Psychic immunity and make Sneasler a Choice Scarf set. You can use Okidogi if you don't mind dropping Sneasler.
Also, I'm curious, did you build the team around Munkidori? Munkidori seems like the kind of Pokemon that you would need to build around and won't be able to just slap it onto a team.
I guess Specs Munkidori is fine, though I've been toying with Nasty Plot + Z-move. Here is the team if you're interested:
https://pokepast.es/dd5cfc99b07da4eb (You could make Munkidori specs and make Toxapex Icium Z)