Help New to Competitive Battling... Need Serious Help

[Burst Ezel]

Hi guys, I'm new to competitive battling and need a bit of help. I always end facing a phermosa and Tapu combo against my tapu koko and Garchomp combo. Garchomp has rocky helmet and tapu wears a ballon. assuming Phermosa's speed is perfect(IV and EVs) and the tapu knows an ice move, how can I beat that combo? Leaning towards not using choice scarf... anyone have some tips?All help is appreciated
Garchomp:
Dragon claw
Poison Jab
Earthquake
Rock Slide

Tapu koko:
Thunderbolt
Brave Bird
taunt
Discharge

 

[Professor Palutena]

In VGC, nothing outspeeds Pheromosa at max speed. You will need a Choice Scarf to outspeed it.

Those two Pokemon on their own can't beat Pheromosa easily, but that's why you have teammates. You may want to look into something like Arcanine, Gyarados, Tapu Fini or Marowak.