I meant Ferrothorn. I swear, I put that twice, and kept changing it (why, idk...).
As for Empoleon, I like him as a support tank, but he cannot learn stealth rock or spikes. No entry hazard for him makes it bad to run roar, but protect isn't as reliable, and he cannot learn defog. The moveset I went for allowed the secondary effects to dominate the opponent, providing him steady health regen, and generally being bulky. I thought of a Rest/Chesto Berry combo, instead of Aqua Ring, but that is only good for one reset. It also still leaves the one move available for him to fill. As a special attacker, his options are severely limited, so I chose Ice Beam, due to its great coverage against Ground and Grass, as well as 10% chance of Freeze.
Hippowdon, I was trying to find a good medium for. You did, and I like it, so I might just use yours. I was trying to make it a reliable attacker, but a tanky like that would be far better, especially against attack sweepers that need a set up. Whirlwind resets that, and with stealth rocks, chip damage wear down. Life Orb users and enemy Talonflames hate that big time.
Greninja had always been a possibility, since it can learn Aerial Ace to cover it's own weakness to grass, and also shutting Breloom down hardcore.
As for Sand Rush Excadrill, I hate it. With a passion. Seriously. I don't have a good reason, but I hesitate to run it as a result. I'd much rather avoid it, if possible.
Metagross, yes, focus sash is an extremely bad idea. I was looking for a good item for him, and couldn't come up with one.
Amoongus, I honestly didn't think of him. And your build is good. If I replace Empoleon, he would be my replacement for him.
Garchomp, I hesitated only for the fact that his weaknesses already exist in my other pokemon. If I wasn't running Tyranitar, he would be in. But right now, him and Tyranitar fill the same slow.
Lucario is in there for Special Attack coverage. Physical Attackers are common, but easy to wear down. Choice Scarf was the first choice of item on him, and would make him easily sweep. I lacked that before, and with Ferrothorn and Rough Skin Garchomp in the OU tier, it definitely chunked them with little repercussion. I decided Air Balloon would be a better idea, as Earthquake, being so common, is one of his biggest banes. Amoongus would be the only pokemon in your list that could fix my reliance on the Attack Stat for damage.
Lastly, I wanted to run a Special Attack Aegislash, again because of my Attack reliance. The Toxic was the only thing I could think of that wasn't physical but could do some damage. Maybe I'm thinking too narrow, but I'm still open to suggestion with him.
I appreciate your input, and will take everything into consideration.
1. Empoleon can learn Stealth Rock either as a Gen IV TM, or a Gen V move tutor in Black 2/White 2.
2. Greninja has a much better option for Grass Pokemon in Ice Beam, as mentioned in the set I posted. Aerial Ace is weak and runs off of its inferior Attack. Only Mega Aerodactyl gets away with using it, since Tough Claws powers it up to usable levels.
3. Why do you hate Sand Rush Excadrill? While it was a pain to deal with in Gen V, due to permanent sandstorm with Sand Stream, it's much more manageable now that Sand Stream got nerfed to last only 5 turns (8 with Smooth Rock attached).
4. Greninja also is a special attacker. If you want a better special attacker over Lucario, use Gengar, as it also helps against the Fighting Pokemon sand teams struggle with:
-Substitute
-Shadow Ball
-Will-o-Wisp
-Sludge Bomb/Sludge Wave/Disable/Taunt
Nature: Timid
EVs: 28 HP/148 SAtk/80 SDef/252 Spe
Item: Black Sludge
or
-Shadow Ball
-Sludge Bomb/Sludge Wave
-Focus Blast/Thunderbolt
-Destiny Bond
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb