Well, After looking at this, I noticed something,
Dusknoir: Take under consideration that without stat boosts, Dusclops with Evoilite can easily deal more damage to bulkier opponents with night shade, but if you prefer Dusknoir, you might want to try something like Brick Break for fighting coverage, you have enough Ice type coverage. And he needs leftovers.
Now to Swampert.... Macho Brace?
Also, Use a Brave Nature.
And fill out your EV's.
Hammer Arm may lower his freasishly low speed, but when it comes to coverage, he's not getting any.
Rock and Steel are already covered by E-quake, and that just leaves it covering normal....
I would ditch this for T-Punch for water or I-Punch for Grass and Dragon.
The Fling Iron Ball trick is neat.
Ampharos, This was missing an item to be filled out. I would say Life orb or Wise Glasses.
Exgecutor, make sure its ability is harvest, and then give it a sitrus berry to hold, OR you can sub Ancient Power for rest, and give it a Lum Berry.
And if this is on PO I would consider swapping Ancient power for a Hidden Power Rock.
Overall this was a nice team, with little quirks, just remember to list abilities next time, because there were pokemon like Exeggutor, that certain strategies only work with certain abilities.