Need advice

[MZAMKR]

I'm newly getting into competition and could use some help.
This is my current team:

Mammoswine: Adamant @Nevermeltice
(252 Atk, 252 Hp, 4 SpDef)
Trait: Thick Fat
Moves:
-Icicle crash
-Earthquake
-Stone Edge
-Ice Shard

Salamence: Adamant @Quick Claw
(252 Atk, 252 Spd, 4 SpDef)
Trait: Moxie
Moves:
-Dragon Claw
-Shadow Claw
-Steel Wing
-Aerial Ace

Porygon Z: Modest @ Shell Bell
(252 SpAtk, 252 Spd, 4 Def)
Trait: Download
Moves:
-Thunderbolt
-Psychic
-Signal Beam
-Shadow Ball

Arcanine: Jolly @Leftovers
(252 Atk, 252 Spd, 4 SpDef)
Trait: Flash Fire
Moves:
-Outrage
-Extremespeed
-Flare Blitz
-Wild Charge

Heracross: Adamant @Heracronite
(252 Atk, 252 Def, 4 SpDef)
Trait: Moxie/Skill Link
Moves:
-Pin Missile
-Arm Thrust
-Bullet Seed
-Rock Blast

Lapras: Modest @Damp Rock
(252 Hp, 156 SpAtk, 100 SpDef)
Trait: Hydration
Moves:
-Rain Dance
-Thunder
-Surf
-Freeze Dry

I just added Lapras. Trying to decide between Kingdra, Lapras, or Empoleon. What do you guys think?
Any advice on move sets or any other aspects of my team would be a great help! I'm new so I'm unsure! Thanks!

 

[wolf]

Mamoswine: Use the Physical Attacker set here. Stealth Rock in particular would be useful to have, while Stone Edge doesn't help Mamo much (Icicle Crash hits Gyarados anyway). Never-Melt Ice and other type-enhancing items are usually inferior to Life Orb. Life Orb is more flexible and boosts every attack by x1.3. On the other hand, Never-Melt Ice only boosts Ice-types moves by x1.2.

Salamence: Use the Dragon Dance set here. Again, Life Orb is the better item here. Salamence needs the power in order to KO Skarmory and Ferrothorn. Quick Claw is too situational.

Porygon-Z: Isn't viable. If you insist on using it, a Choice Scarf set would probably be the most effective, mainly because the Scarf will patch up its low Speed. Choice Specs could be used, but Exploud does a better job at that thanks to learning Boomburst.

Porygon-Z @ Choice Scarf
Ability: Adaptability
EVs: 4 Def / 252 SpA / 252 Spd
Timid Nature
- Tri Attack
- Dark Pulse
- Ice Beam
- Hidden Power Fighting / Trick

Tri Attack for STAB; Dark Pulse for Ghost-types; Ice Beam for Dragon-types; HP Fighting for Tyranitar, Heatran, etc.; and Trick for crippling an opposing Pokemon, especially a wall. Adaptability for its reliability to boost Tri Attack and help P-Z potentially pull off a late-game sweep.

Arcanine: Use the Offensive set here. Regardless, Arcanine isn't viable. Talonflame, Victini, and Entei all generally perform the physically offensive Fire-type role better.

Heracross: Use the Offensive set here.

Lapras: Isn't viable. Out of the Pokemon you listed, I'd say that Kingdra would be best for your team. It helps weaken Fairy-types and the like so that Salamence can come in and sweep. Try out either of these sets.

 

[Nah]

Out of the Pokemon you listed, I'd say that Kingdra would be best for your team. It helps weaken Fairy-types and the like so that Salamence can come in and sweep. Try out either of these sets.

Did you mean Empoleon? Kingdra isn't something most Fairies are scared of. Empoleon's Steel typing would be more beneficial to the team than adding another Dragon (Though Sniper Kingdra can be nice).
These Empoleon sets are still usable.

I think that the Mamoswine set in the OP is usable as well, though like wolf said, a different item is needed.

 

[PlatinumDude]

To add to Wolf's post:

Lum Berry is also a viable option on Salamence to let it cure status mid-sweep, like burn, paralysis or post-Outrage confusion.

Kingdra is still weak to Fairy. Just putting that out there. Better ideas for Fairy checks/counters include Gengar, Metagross, Aegislash, Ferrothorn and Genesect:

Ferrothorn:
Ferrothorn:
-Stealth Rock/Spikes
-Leech Seed
-Power Whip/Protect
-Gyro Ball/Thunder Wave
Nature: Relaxed
EVs: 252 HP/208 Def/48 SDef
Item: Leftovers
Ability: Iron Barbs

Gengar:
-Shadow Ball
-Sludge Bomb/Thunderbolt
-Focus Blast
-Destiny Bond
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb/Focus Sash

or
-Substitute
-Shadow Ball
-Focus Blast/Pain Split
-Disable/Will-o-Wisp/Focus Blast
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Black Sludge/Life Orb

Aegislash:
-Shadow Ball
-Iron Head/Shadow Sneak
-Sacred Sword/Shadow Sneak
-King's Shield
Nature: Quiet
EVs: 240 HP/252 SAtk/4 SDef/12 Spe
Item: Leftovers

or
-Shadow Ball
-Shadow Sneak
-Sacred Sword
-Iron Head/King's Shield
Nature: Quiet
EVs: 252 Atk/252 SAtk/4 SDef
Item: Leftovers/Life Orb

or
-Swords Dance
-King's Shield/Shadow Claw
-Shadow Sneak
-Sacred Sword
Nature: Adamant
EVs: 240 HP/252 Atk/4 SDef/12 Spe
Item: Leftovers

or
-Swords Dance
-Autotomize
-Shadow Claw
-Sacred Sword
Nature: Adamant
EVs: 84 HP/252 Atk/4 SDef/168 Spe
Item: Leftovers

or
-Autotomize
-Shadow Ball
-Hidden Power (Ice)
-Sacred Sword/Iron Head/Flash Cannon
Nature: Rash/Modest
EVs: 88 Atk/252 SAtk/168 Spe
Item: Life Orb/Weakness Policy

Metagross:
-Stealth Rock
-Meteor Mash
-Earthquake
-Bullet Punch/Pursuit/Trick
Nature: Adamant
EVs: 252 HP/252 Atk/4 Def
Item: Leftovers/Iron Ball
Ability: Clear Body

or
-Meteor Mash
-Earthquake
-Bullet Punch
-Zen Headbutt/Pursuit
Nature: Adamant
EVs: 252 HP/252 Atk/4 Def
Item: Assault Vest
Ability: Clear Body

Genesect:
-U-turn
-Ice Beam
-Flamethrower
-Bug Buzz/Thunderbolt
Nature: Hasty/Naive
EVs: 4 Atk/252 SAtk/252 Spe
Item: Choice Scarf/Expert Belt/Life Orb/Focus Sash

or
-Shift Gear
-Iron Head
-Extreme Speed
-Blaze Kick/X-Scissor
Nature: Hasty
EVs: 24 HP/252 SAtk/8 SDef/224 Spe
Item: Life Orb

or
-U-turn
-Iron Head
-Extreme Speed
-Flamethrower/Ice Beam
Nature: Hasty
EVs: 252 Atk/4 SAtk/252 Spe
Item: Choice Band

or
-U-turn
-Iron Head
-Ice Beam
-Explosion
Nature: Hasty/Naive
EVs: 252 Atk/4 SAtk/252 Spe
Item: Choice Scarf

Really, I don't know if Empoleon is that viable, but if you want to try it, go ahead:
-Substitute
-Agility
-Surf
-Ice Beam/Grass Knot
Nature: Modest
EVs: 12 HP/4 Def/252 SAtk/240 Spe
Item: Petaya Berry
Ability: Torrent

or
-Hydro Pump
-Ice Beam
-Grass Knot/Hidden Power (Grass)
-Surf/Flash Cannon
Nature: Modest
EVs: 200 HP/252 SAtk/56 Spe
Item: Choice Specs
Ability: Torrent

or
-Stealth Rock
-Scald
-Toxic/Roar/Defog
-Protect/Ice Beam/Defog
Nature: Calm
EVs: 248 HP/44 Def/216 Spe
Item: Leftovers
Ability: Torrent

 

[wolf]

Did you mean Empoleon? Kingdra isn't something most Fairies are scared of. Empoleon's Steel typing would be more beneficial to the team than adding another Dragon (Though Sniper Kingdra can be nice).
These Empoleon sets are still usable.

Well, I was thinking Kingdra could significantly weaken them with rain-powered Water attacks. But after doing some calcs, it doesn't seem too powerful to pull that off. Oh well!