First off here's a post by D_A, a little rude but I think it gets the point across: http://www.pokecommunity.com/showpost.php?p=5574293&postcount=9
Alright, Garchomp is Uber now so you can't use him. Also, I think Empoleon just adds to the Fighting / Ground weakness.
Instead I'd replace Empoleon with something like:
112 HP / 252 Sp. Attack / 144 Speed
This lets you come in on Politoed, Gyarados, basically any powerful Water type Pokemon. Since you have plenty of power on the Physical side in your team, I'd suggest Latias in your slot where Garchomp used to be so you'll be able to come in on powerful Fighting types:
252 HP / 4 Sp. Attack / 252 Speed
That lets you take on those pesky Ferrothorns as well. It gives you another Pokemon to set up on stuff, and just really helps balance it out altogether.
Lastly a couple changes to your existing stuff. Excadrill either wants to be Jolly with Life Orb, or Adamant with Balloon. It lets you OHKO things like Jellicent after a SD. Also, since you aren't running stall, Skarmory would be better off running Stealth Rock > Spikes, though with the highly offensive nature of the team I don't really see where he fits in. Good luck with the team. :D