Ferrothorn, Amoongus, and Porygon2 can't outspeed anything, so speed investment is wasted on them. Move the EVs to HP.
Explosion will only do a little bit more damage than gyro ball, and gyro ball doesn't cause the user to faint, so replace Ferrothorn's explosion with gyro ball. Quick claw is unreliable, so replace it with leftovers.
Volcarona's defenses are so low that physical defense EVs won't do much should have a timid nature and max speed so it can outspeed as much as possible.
Effect spore has no effect on sleeping opponents and is still unreliable when they're awake, so it should be replaced with regenerator. Amoongus can never be very offensive, so move the special attack EVs to HP and defenses and replace meadow plate and energy ball with black sludge and giga drain.
Replace Porygon2 with Zapdos if you want a special tank.
Charizard isn't threatened by anything that's weak to crunch, so replace that with earthquake.
Gyarados is too slow to be an all-out attacker. Replace it with Salamence.
