7th Gen Party Help

Aloha trainers,

It's been forever since I've been here thanks to work and life etc! I've started playing Ultra Sun recently and I said to myself "I'm not gonna make the same mistake I made in Sun" however I have xD

In sun I kinda got carried away and ended up with 12 Pokemon I was using throughout the game, so you Can imagine when I got to the elite 4 my guys were not ready! Well, I've just beaten Sophocles Trial and my way to my next one and I've made the same mistake again!!

I need some advice who to use going forward for the rest of the game. I'm after my ultimate 6! I'm willing to bench and add new Pokemon if the recommendations tickle my fancy too!!

So here's who I have;

Growlithe (Arcanine) - Willing to swap - maybe Alohan Marowak?
Goomy (Goodra)
Pikachu (Alolan Raichu)
Mudsdale
Snorlax
Decidueye - Willing to bench
Primarina
Bewear
Lucario - willing to bench
Dusk Lycanroc
Umberon

As you can see again I've got carried away thanks to my Pokebank and underestimating how many cool Pokemon are available in this game.

Any advice, recommendations you can give me I would truly appreciate :3

I would use 6 different types on my team. Decidueye for grass type, Arcanine for fire type, Primarina for water type, Alolan Raichu for electric type, Alolan Marowak for for fire/ghost type and it can also learn good ground type moves, and Goodra for dragon type.

That's what I'm trying to achieve :3 I just don't know who to use for the other 2/3 spaces :3