Hello. You have good pokemons in your current team. The only problem is the moves that you use. Some pokemons just don't have the stats to use special moves.
For example, Snorlax, Absol and Sandslash are physical pokemons. They won't be efficient if you use moves such as Frost breath, Shockwave, Charge beam or Flamethrower, which are good moves but special ones.
Additionally, some of your team lacks STAB moves. I don't know if you're familiar with that term. But a Normal move used by a Normal pokemon will be enhanced by 50%. For example, Snorlax and Absol haven't any ...
Here is my advice. Go to the Circus and use Heart Scales in order to teach your team old moves:
Alolan Sandslash: Icicle Crash instead of Frost breath. The best physical ice move. Versus Blake who will set Hail, Sandslash will outspeed everyone with his ability. Fern's Grass types will be destroyed.
Snorlax : Body Slam in priority then Crunch. You don't need Shockwave and Metronome. Snorlax win't make use of these moves.
Druddigon: Surf and Flamethrower ain't very useful imo. You can try Superpower instead.
Absol: This guy is very frail. You were talking about Mamoswine earlier and it will help with moves such as Earthquake and Icicle Crash. However, if you keep him, try using Sword Dance, Night Slash, Sucker Punch, Psycho Cut and Detect (useful in double battles).
Malamar is ok, especially if you spam Superpower with Contrary ability. you can replace Pluck with Light Screen or Reflect which can be useful in double battles too.
Blastoise : Just use Hydro Pump instead of Waterfall (you can switch between Brick Break and Waterfall). Yes, it can miss but it's deadly powerful. If you're afraid of that, try an item that improve your accuracy.
If you lack of Heart Scales, go to the mountain and mine some rocks. Good luck!