I'm mostly just going to repeat what I said in my comment, but also work on the defensive side of this team.
Abomasnow -> Alolan Ninetales
Alolan Ninetales is better then Abomasnow in nearly every way. It gets Fairy STAB, is much faster, and has useful utility moves like Encore and Hypnosis.
Ninetales-Alola @ Icy Rock
Ability: Snow Warning
EVs: 252 HP / 4 SpA / 252 Spe
Timid Nature
- Aurora Veil
- Freeze-Dry / Blizzard
- Moonblast
- Hypnosis / Encore
Icy Rock is used instead of Light Clay as Hail turns are more important then Aurora Veil turns. Blizzard can be used as Ice STAB instead of Freeze Dry, but Freeze Dry is generally better as it can easily take care of water types like Swampert or Slowking.
Arctozolt
For Arctozolt, it should be more of a mixed sweeper with Bolt Beak. Bolt Beak is too good to give up for a special set. Try something like this:
Arctozolt @ Life Orb
Ability: Slush Rush
EVs: 252 Atk / 4 SpA / 252 Spe
Naive Nature
- Bolt Beak
- Blizzard
- Freeze-Dry
- Low Kick / Stomping Tantrum
Bolt Beak is your main move of choice, but if there's a ground type you should use Blizzard. Freeze Dry is for Swampert.
Beartic -> Alolan Sandslash
Switch Beartic to Alolan Sandslash, which generally better Slush Rush Swords Dance sweeper due to it's higher bulk and Steel typing.
Sandslash-Alola @ Wide Lens
Ability: Slush Rush
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Swords Dance
- Knock Off
- Earthquake
- Triple Axel
Wide Lens is good to near guarantee Triple Axel hits all three times. Earthquake is for Heatran and other steel types, while Knock Off is good for Slowking and removing items from Pokemon dependent on them.
Froslass -> Dragapult
Dragapult is a faster offensive Ghost type that can help the team against some Steel types that it struggles with like Ferrothorn. It also is great speed control for when Hail isn't up.
Dragapult @ Choice Specs
Ability: Infiltrator
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Shadow Ball
- Draco Meteor
- U-turn
- Flamethrower
Choice Specs maximizes Dragapults offensive power. Shadow Ball is your main move, and Draco Meteor can be used to decimate a Pokemon of your choice. Flamethrower is a reliable option to hit Steel types, but Fire Blast can be used instead for a higher power, but more risky alternative.
Articuno -> Mandibuzz
Mandibuzz is a much better Flying type than Articuno, and it provides the team with Defog support.
Mandibuzz @ Heavy-Duty Boots
Ability: Overcoat
EVs: 248 HP / 108 Def / 152 SpD
Impish Nature
- Foul Play
- Roost
- Defog
- U-turn
Mandibuzz's mixed defenses lets it check Rillaboom and Dragapult much easier. Foul Play punishes physical attackes, and U-turn is great for pivoting.
Frosmoth -> Swampert
Swampert patches a bunch of the holes in this team, namely the weaknesses to Fire and Electric, as well as functioning as a specially defensive pivot.
Swampert @ Leftovers
Ability: Damp
EVs: 252 HP / 4 Def / 252 SpD
Sassy Nature
IVs: 0 Spe
- Stealth Rock
- Flip Turn
- Earthquake
- Toxic
A Sassy Nature and 0 Speed IVs lets Swampert provide a slow Flip Turn. Earthquake is great STAB, and Toxic can cripple defensive Pokemon.
Here's a Pokepaste.
