First, it's helpful if you include things like the Nature, EVs, Ability, and the item you plan to equip on these Pokemon. These things are VERY important.
Just a quick glance...
The Metagross' moveset is fairly average - I'd recommend Meteor Mash over Earthquake, if not just because you have a few other Pokemon with Earthquake already so Ground-type moves are fairly covered. Plus, Meteor Mash + Bullet Punch is a great counter for some Focus Sash'd leads, like Aerodactyl.
Empoleon
Hydro Pump / Surf is just a classic Power or Accuracy debate, and is entirely your call. Also, why does it have Sleep Talk? Unless you're running Rest on it for a RestTalk set, you're basically going to have to predict when a Sleep-move is coming and make Empoleon take it. But then you lose'll your ability to counter. Use HP Electric, as it'll give you better coverage.
Breloom
There's really no reason to have Spore AND Stun Spore, as you can't use both on the same Pokemon. Stun Spore gives your Paralyze, which will lower their speed and has a 25% of making them skip their turn, but at a 75% Accuracy rate. Spore is 100% Accuracy, but sleep naturally wears off. I'd recommend Spore, just because it's 100% chance. As far as the movepool, drop one of the "spores" for Substitute. Make sure you run Toxic Orb and Poison Heal, as this will recover more HP then Leftovers. I'd say keep Seed Bomb as well, for the STAB.
Gyarados
Generic DD Gyarados is generic. Nothing to say here, as you can read it on smogon.
Mamoswine
Physical attacker set, pretty standard. Again, anything I can say has been said on smogon.
Honchkrow
This is pretty much a mixed attacker which... there are better mixed attackers out there then Honchkrow, and I should also note that he's the only Pokemon on your team that has a Fire, Dark, or Flying-type move.
My overall opinion is to maybe drop Mamoswine and Honchkrow and pick up another special attacker and probably a wall or some sort of support. A RestTalk Snorlax is usually what I like to use. He's a good stall and has pretty nice DEF and SpD stats, so he can switch in to take hits or Thunderwaves or Spore and Rest it allll away, and then Sleep Talk-Body Slam the poop out of things. :D
Alakazam or Gengar make good SpA Pokemon, though their pretty frail. There's a good offensive Zapdos build on smogon that has EXCELLENT type coverage as well.
