Mega Sharpedo/Camerupt Quest - Water Race Many Encounters

[Aggoggos]

Hello,

I've been trying to do the quest and in the water race i encounter normal pokemons instead of just the high level ones making me waste time. I tried repeling the low level pokemons and encounter only the high level ones. I get so many high level pokemons and even though i use Ludicolo with choice specs and oneshot mostly every encounter, i still cant finish in time. I watch guide videos and without repels they encounter only the high level pokemons and like max 10 of them in the whole run. I, on the other hand, encounter 3-4 high level pokemons before even reaching the first checkpoint. By the time i get to 2/3 of the map, i run out of time. In one of the videos i watched, a guy passed 2 checkpoints with 0 encounters. How is this even possible?