This team is best played like a protect-the-carry team.
You are not trying to win by attacking straight away every game. You are trying to pick one Pokémon that can win the matchup, protect it for a turn or two, let it boost, then start attacking.
The three main “carries” are:
Annihilape
This is your physical win condition. Maushold can use Beat Up into it to power up Rage Fist, or use Follow Me to help it get a safe Bulk Up.
Mega Delphox
This is your special sweeper. You want to give it one safe Nasty Plot turn, then start clicking Heat Wave or Psyshock.
Mega Raichu-Y
This is your fast special pressure option. It can Nasty Plot, then threaten Zap Cannon damage and paralysis.
The support Pokémon are there to make that happen.
Maushold protects your setup Pokémon with Follow Me and Friend Guard. It also powers up Annihilape with Beat Up.
Incineroar buys safe turns with Fake Out, Intimidate, Will-O-Wisp, and Parting Shot.
Grimmsnarl makes the whole team harder to kill with Reflect and Light Screen, then uses Scary Face to slow things down.
The easiest way to play it is:
Pick your carry.
Protect it.
Boost once.
Start attacking.
For example, if Annihilape looks good, lead Maushold + Annihilape. If they can’t threaten Ape much, use Beat Up into your own Annihilape and start building Rage Fist power. If they can hit Ape hard, use Follow Me while Annihilape Bulks Up first.
If Delphox looks good, lead Incineroar + Delphox or Maushold + Delphox. Use Fake Out or Follow Me to give Delphox a free Nasty Plot, then start attacking with boosted Heat Wave.
If the opponent is really aggressive, lead Grimmsnarl and set the right screen first. Reflect into physical teams, Light Screen into special teams. After that, bring in your carry and play slower.
The biggest mistake with this team is trying to set up too much. You do not need both screens, Bulk Up, Nasty Plot, and perfect positioning every game. Usually one safe boost is enough.
Also be careful with Annihilape’s Earthquake because your own side does not have a Ground immunity. Only click it when your partner is protecting or when it clearly wins the turn.
So in simple terms:
This team wins by making one Pokémon really hard to kill, boosting it once, then forcing the opponent to deal with it while Maushold, Incineroar, and Grimmsnarl keep protecting it.