All-out attacking Sneasel should run Life Orb, as it's not that strong without Swords Dance:
-Knock Off
-Ice Punch
-Pursuit
-Ice Shard
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Life Orb
Abiilty: Inner Focus
Even though Flare Boost is unique to Drifblim, it's not worth using. Its move pool is decent, sure, but it lacks a good Flying STAB outside of item less Acrobatics (no, Air Cutter doesn't count because of its poor base power). Drifblim's main niche is Unburden, which allows it to outspeed a lot of things once activated, though it will wear off if Drfiblim leaves battle, so you only have one shot to sweep with it:
-Calm Mind
-Shadow Ball
-Hidden Power (Fighting)/Thunderbolt
-Rest
Nature: Modest
EVs: 8 HP/32 Def/252 SAtk/40 SDef/176 Spe
Item: Chesto Berry
Ability: Unburden
or
-Acrobatics
-Will-o-Wisp
-Substitute
-Knock Off/Destiny Bond
Nature: Adamant
EVs: 12 HP/252 Atk/32 Def/36 SDef/176 Spe
Item: Sitrus Berry/Liechi Berry
Ability: Unburden
Golem should be played in the lead position. Setting up with Power-Up Punch isn't worth it, as it would rather go boom with Explosion or have priority with Sucker Punch:
-Stealth Rock
-Stone Edge/Rock Blast
-Earthquake
-Explosion/Sucker Punch
Nature: Adamant
EVs: 252 Atk/4 Def/252 Spe
Item: Normal Gem/Custap Berry
Ability: Sturdy
Mega Camerupt does fine with its STABs alone; Flash Cannon doesn't do anything noteworthy. Also, Lava Plume is completely useless on it because its burn effect is negated by Sheer Force:
-Fire Blast
-Earth Power
-Hidden Power (Electric)/Stealth Rock
-Will-o-Wisp/Substitute
Nature: Modest
EVs: 92 HP/252 SAtk/164 Spe
Item: Cameruptite
Ability: Solid Rock
Walrein isn't that good, mainly because its niche of a hail staller was significantly nerfed, due to the fact that Snow Warning only lasts for 5-8 turns. It's also badly outclassed by the other Water Pokemon in NU, like Samurott, Prinplup, Qwilfish, Lanturn and Mantine, mainly because of better offensive presence and/or utility. Besides, you already have an Ice Pokemon in Sneasel, and given how defensively bad Ice is, it's not worth using 2 or more of them.
Samurott:
-Swords Dance
-Waterfall
-Megahorn
-Aqua Jet
Nature: Adamant
EVs: 120 HP/252 Atk/136 Spe
Item: Mystic Water/Splash Plate/Life Orb/Lum Berry
Ability: Torrent
or
-Hydro Pump
-Ice Beam
-Grass Knot
-Taunt/Aqua Jet/Knock Off/Superpower
Nature: Modest/Rash
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb
Ability: Torrent
Prinplup:
-Stealth Rock
-Scald
-Defog
-Toxic
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Eviolite
Ability: Torrent
Qwilfish:
-Spikes
-Waterfall/Scald
-Taunt
-Thunder Wave/Toxic
Nature: Impish/Bold
EVs: 252 HP/160 Def/96 Spe
Item: Black Sludge
Ability: Intimidate
Lanturn:
-Scald
-Volt Switch
-Heal Bell
-Toxic/Thunder Wave
Nature: Calm
EVs: 40 HP/252 Def/216 SDef
Item: Leftovers
Ability: Volt Absorb
Mantine:
-Scald
-Air Slash
-Defog
-Toxic
Nature: Calm
EVs: 248 HP/252 Def/8 SDef
Item: Leftovers
Ability: Water Absorb
Choice Band severely limits Electivire because it likes to switch moves to make the most out of its good coverage. Once again, Power-Up Punch isn't worth using:
-Wild Charge
-Cross Chop
-Ice Punch
-Hidden Power (Grass)
Nature: Naive
EVs: 252 Atk/4 SAtk/252 Spe
Item: Life Orb/Expert Belt
Ability: Motor Drive
A Grass Pokemon should be considered on this team, mainly because they cover both of Camerupt's weaknesses very nicely. Options are Lilligant, Exeggutor, Quilladin, Leafeon, Vileplume and Tangela:
Lilligant:
-Quiver Dance
-Giga Drain
-Hidden Power (Fire/Ice)
-Sleep Powder
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb/Lum Berry
Quilladin:
-Spikes
-Wood Hammer
-Roar
-Synthesis
Nature: Impish
EVs: 252 HP/252 Def/4 SDef
Item: Eviolite
Ability: Bulletproof
Vileplume:
-Giga Drain
-Sludge Bomb
-Sleep Powder/Aromatherapy
-Synthesis/Moonlight
Nature: Bold
EVs: 248 HP/252 Def/8 SDef
Item: Black Sludge
Abilty: Effect Spore
-Giga Drain
-Sludge Bomb
-Hidden Power (Fire)/Sleep Powder
-Moonlight/Synthesis
Nature: Modest
EVs: 116 HP/252 SAtk/140 Spe
Item: Life Orb
Ability: Effect Spore
Leafeon:
-Swords Dance
-Leaf Blade
-Knock Off
-Synthesis/Natural Gift
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb/Watmel Berry
Tangela:
-Leaf Storm
-Giga Drain/Ancient Power
-Hidden Power (Fire)
-Sleep Powder
Nature: Modest
EVs: 248 HP/252 SAtk/8 SDef
Item: Eviolite
Ability: Regenerator
or
-Giga Drain
-Hiddne Power (Fire)
-Sleep Powder/Toxic
-Leech Seed/Synthesis
Nature: Bold
EVs: 248 HP/252 Def/8 SDef
Item: Eviolite
Ability: Regenerator