Hey Itachi, good battle!
You gotta be careful with Porygon-Z... was it holding a Choice Scarf? Eh, he was dead either way. I guess that was a cheap trick, but when there's a whole team full of Pokemon you're going up against, it's best to predict a switch and attack accordingly, especially when holding a Choice item. Ice Beam, or even Tri-Attack, would have been death to Dugtrio.
Also, your physical sweepers far outweigh your special sweepers, so you may want to consider an Aromatherapy/Heal Bell Pokemon in case someone wants to go Burn happy, like my Spiritomb. A Burn cuts Attack in half, so it pretty much rendered your Garchomp and Rhyperior useless.
Good team nonetheless! Rhyperior is a bit over rated, but he can be a menace when his counters (fast special sweepers with Water or Grass attacks) are taken out.