Hey there! A very fine team here--there's nothing much to say, haha! However, I did notice some problems in your team, and I will mention them alongside the appropriate solution!
- so you've got a really nice set here, but I don't see the point of running Rocky Helmet if you aren't going to go for offensive rock / bulky rock setter. There are many items you could use, such as Leftovers or Focus Sash, or maybe Lum Berry and then Outrage > Dragon Claw.
- now Weavile isn't supposed to be in the field for too long; it's role is to get out there, and deal as much damage it can do before fainting, and there's no point crying over spilt milk when it dies, so I suggest changing Focus Sash to Life Orb as this makes sure Weavile can deal a lot of damage whilst it is alive. I'd also go for Ice Shard + Icicle Crash > Swords Dance + Ice Punch. Ice Shard gives your team another form of priority, and Icicle Crash deals a lot of damage to Dragonite, Landorus and Serperior. Setting up does limit Weavile's time in the field, when it could just be KO'ing mons.
- Ferrothorn is often used as a rocks setter, so if you're going to be using it, it's generally advised that you give it Spikes / Stealth Rock, else there is no bother using it, to be honest.
- Azumarill does need the Speed due to its poor Speed stat, which is why it is almost crucial to run Speed EVs on it. There's also no need to make it bulky; 4 HP / 252 Atk / 252 Speed would suffice! You're also not going to want Aqua Ring - once Belly Drum is up, Azumarill needs the coverage to be able to hit a range of Pokemon. You have to options for this; Knock Off to hit Ghost- and Psychic-types such as Gengar, Alakazam and Latios, and OHKO them, or Superpower for the Steel-types that pressurize Azumarill with their super effective STAB moves.
As for your Doubles team, I think Cresselia does stand out. Suitable partners for it, in an ideal Trick Room team (Cresselia's main niche is Trick Room, so it's best to build your team around it if you want to use it) are Kangaskhan (one of the best Doubles Pokemon), Heatran, Landorus-T, Amoongus, Sylveon, Suicune, etc! There's so much to choose from, so explore, and find the ones you like.
Good luck, and I hope I helped!
I hope I helped. Good luck :)
