Is my Gen-9 OU team good? I based it off of a Fire-Water-Grass Core team I saw a while ago. I'm not a competitive player, this is the first "competitive" team I have made. What improvements could be made?

Here's the poke paste: https://pokepast.es/5f4ad009c21a1253

I decided to go with H. Arcanine, Amoonguss, and Rotom-Wash as my Core's F-G-W Pokémon.

Rock Head Arcanine with Choice Band and Rock Head to dish out strong attacks without worrying about Recoil.

Amoonguss is the Bulky Pivot/Stall that is there to absorb attacks and stall with Leftovers and Toxic, and it can keep itself relatively healthy with Synthesis, and break down setups with Clear Smog.

Rotom-Wash serves as the Bulky Special Attacker. I gave it Will-O-Wisp for some extra chip damage.

Landorus is mainly there to set up Stealth Rock, and I gave it Taunt so that opposing Pokémon can't set up hazards on us. (I accidentally gave it Earth Power, forgive me, supposed to be earthquake)

Kingambit is basically the Revenge killer of this team, with Supreme Overlord and Kowtow Cleave, it can hit others pretty hard after just 3 dead pokemon and still decently sustain itself with leftovers.

Finally, Dragapult is the speedy Special Attacking Choice Specs monster. I also gave it U-turn so it can safely pivot out of unfavorable matchups