While Bronzong certainly has the bulk to trigger Weakness Policy, it's not really strong enough to make the most out of the boosts. The loss of Leftovers will make it worn down faster. A better replacement is Celebi, which, despite the fact it has more weaknesses, is bulkier and has access to reliable recovery:
-Stealth Rock/Healing Wish/Perish Song
-Giga Drain
-Baton Pass/Thunder Wave
-Recover
Nature: Bold
EVs: 252 HP/156 Def/84 SDef/16 Spe
Item: Leftovers
Tyranitar isn't a bad Mega by any means, but it faces stiff competition from its fellow Megas. Honestly, the best Mega Tyranitar can do is Dragon Dance, but even that faces competition from Mega Altaria, Mega Gyarados, and Charizard X. You're better off using regular Tyranitar, as it has less opportunity cost. Torment is a gimmicky attack, while Ancient Power is a weaker STAB than Stone Edge:
-Stealth Rock
-Stone Edge
-Pursuit
-Crunch/Ice Beam/Fire Blast
Nature: Relaxed
EVs: 248 HP/80 Def/180 SDef
Item: Smooth Rock/Leftovers
Ability: Sand Stream
or
-Stone Edge
-Crunch/Ice Punch
-Pursuit
-Superpower
Nature: Jolly/Adamant
EVs: 252 Atk/4 Def/252 Spe (Jolly) or 100 HP/252 Atk/156 Spe (Adamant)
Item: Choice Scarf (Jolly)/Choice Band (Adamant)
Ability: Sand Stream
The rest of the team is either terrible, or outclassed.
Excadrill should replace Nidoqueen, as it has Sand Rush to benefit from Tyranitar's sandstorm:
-Earthquake
-Iron Head
-Rock Slide
-Rapid Spin/Swords Dance
Nature: Adamant/Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Life Orb/Air Balloon
Ability: Sand Rush
Either one of the Mega Charizards should be used over their regular counterpart, as both are stronger. They also appreciate Tyranitar's Pursuit support to get rid of the Lati twins, who otherwise check/counter them. Even then, Fling + Acrobatics is a bad combo, and Charizard X does physical attacking better than its normal counterpart, courtesy of Tough Claws and better Attack. Charizard Y does its regular counterpart's job of breaking through things in general much better, as it has Drought to negate its Water weakness, boost its Fire STAB, as well as making Solar Beam a 1-turn attack and a reliable way to take out Water, Ground, and Rock Pokemon:
-Dragon Dance
-Flare Blitz
-Dragon Claw
-Roost/Earthquake
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Charizardite X
Ability: Blaze
or
-Flare Blitz
-Dragon Claw/Earthquake
-Will-o-Wisp
-Roost
Nature: Adamant
EVs: 248 HP/24 Atk/180 SDef/56 Spe
Item: Charizardite X
Ability: Blaze
or
-Swords Dance
-Tailwind
-Flare Blitz
-Outrage
Nature: Adamant
EVs: 40 HP/252 Atk/216 Spe
Item: Charizardite X
Ability: Blaze
or
-Fire Blast/Flamethrower
-Solar Beam
-Focus Blast
-Roost
Nature: Timid/Modest
EVs: 4 Def/252 SAtk/252 Spe
Item: Charizardite Y
As a defensive Dragon, Druddigon is outclassed by Garchomp, which has better overall bulk and offensive presence, as well as STAB on its Earthquake:
-Stealth Rock
-Outrage/Dragon Claw
-Earthquake
-Fire Blast/Swords Dance
Nature: Naive/Jolly
EVs: 252 Atk/4 SAtk/252 Spe
Item:Lum Berry/Focus Sash/Rocky Helmet
or
-Stealth Rock
-Dragon Tail
-Earthquake/Toxic
-Fire Blast/Toxic
Nature: Impish
EVs: 252 HP/164 Def/76 SDef/16 Spe
Item: Rocky Helmet
Ability: Rough Skin
Castform is one of the worst Pokemon to use in an OU team. 70 stats across the board isn't enough to make it threatening, despite its wide move pool and ability to abuse weather. Instead of Castform, why not use a better special attacker, like Keldeo, Raikou, Thundurus, or Manaphy?
Keldeo:
-Hydro Pump
-Secret Sword
-Scald
-Icy Wind/Hidden Power (Bug/Electric)/Taunt
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Specs/Choice Scarf/Life Orb
or
-Calm Mind
-Scald
-Secret Sword
-Substitute
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Leftovers
Raikou:
-Thunderbolt
-Volt Switch
-Hidden Power (Ice)
-Extrasensory/Shadow Ball
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Specs/Assault Vest
Thundurus:
-Thunderbolt
-Hidden Power (Ice)/Grass Knot
-Focus Blast/Grass Knot
-Thunder Wave
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb
Ability: Prankster
or
-Nasty Plot
-Thunderbolt
-Hidden Power (Ice)/Grass Knot
-Focus Blast/Thunder Wave
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb
or
-Thunderbolt
-Knock Off
-Superpower
-Hidden Power (Ice)/Grass Knot
Nature: Naive
EVs: 68 HP/188 SAtk/252 Spe
Item: Life Orb
Ability: Defiant
Manaphy:
-Tail Glow
-Scald
-Ice Beam
-Energy Ball/Psychic/Hidden Power (Fire)
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Leftovers
or
-Tail Glow
-Rain Dance
-Scald
-Energy Ball/Ice Beam/Psychic
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Leftovers
or
-Calm Mind
-Scald
-Rain Dance
-Rest
Nature: Bold
EVs: 252 HP/240 Def/16 Spe
Item: Leftovers
