Alrighty, I can tell did this in a hurry because I see a lot of mistakes that you know not to make. It seems that in the past you were always rating my teams, well now I'm gonna rate yours, so here goes nothing.
Tyranitar - Tyranitar looks great, I prefer a Dragon Dance set for early sweeping but that is purely personal preference. I notice you are missing another 104 EVs, you might wanna invest those in Defense for more bulk, or you could give them to Speed for more sweepiness.
Ferrothorn - Couldn't be better
Hippowdon - Looks good, the only thing I see wrong is that you have Spdef EVs on what you stated was a physical wall, an whether Curse is their for that reason or not idk but I figured I would at least point it out. You might throw Stealth Rock in their somewhere but replacing any of those moves would ruin the set.
Thundurus-T - I love this guy <3. I realize you are trying to go a bit different than the norm but why do you have U-turn instead of Volt-Switch? V-Switch gets STAB, and hits way harder on the way out thanks to your 252 spatk. I would replace U-turn for Volt-Switch and take away the 4 atk and put it into HP. I realize that you might have U-turn so he can still escape in the midst of a ground type switch in but lets face it, Volt Switch hits harder and you will be mocing before most ground types, so you will have a chance to HP Ice them.
Starmie - Dat sexy star couldnt get any better.
Gyrados - This guy is devastating, and your set looks good, but I would suggest Stone Edge over Ice Fang to hit other Gyrados, and since Stone Edge and Ice Fang have the nearly the same coverage, you won't be missing out much in that aspect. Also, I'm pretty sure you already know this, but Moxie > Intimidate.
Sorry if there wasnt a lot but the team was looking good and there wasnt a whole lot to do.