Arcanine: Choice Band Arcanine is pretty good. You don't have to change your Arcanine to the set I'm about to recommend, but I do want to point out that a bulky set exists to take advantage of Intimidate
Arcanine @ Heavy-Duty Boots
Ability: Intimidate
EVs: 248 HP / 12 Def / 248 Spe
Timid Nature
- Flamethrower
- Toxic
- Morning Sun
- Teleport
Flygon: Crunch and Thunder Punch seem kind of useless on the set. They don't cover any weaknesses.
Flygon @ Lum Berry
Ability: Levitate
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Dragon Claw
- Earthquake
- Fire Punch / Iron Tail / Substitute
- Dragon Dance
I would change the nature from Jolly to Adamant to outspeed scarfers. I would also replace 4 SpD with 4 HP, since Flygon is Stealth Rock resistant so it can afford to run 4 HP EVs.
Bronzong: 4 Attack EVs do nothing; Body Press does damage based off of the user's Defense stat. You should opt for 252 / 148 / 108 EVs in defenses, and you can run Impish nature over Careful for a more powerful Body Press. Also, Protect is kind of pointless. You can use something like Gyro Ball instead. If you want to run Gyro Ball, you can take 4 Special Defense EVs and put them into Attack.
Blastoise: Blastoise is good, although Focus Sash is always an option
Zoroark: Zoroark is good
Roserade: Extrasensory is pretty bad coverage. You should replace it with Spikes maybe? Or you can replace Extrasensory with a STAB move and use Spikes over Leech Seed
Hope this helps!