How well would this Surfquake doubles team work?

Question

Edit This set is for any Battle Frontier or similar area where all of these Pokemon, their items, and their moves are available.
(XY, OrAs, SM, UsUm)

Latios @ Latiosite
Ability: Levitate
EVs: 4 Hp / 252 Sp.a / 252 Spd
Modest Nature

• Surf (Primary Attack)
• Ice Beam (Coverage)
• Dragon Pulse (STAB Damage)
• Psyshock (Not being completely walled by Sp.d walls)

This is the core of the team along with Metagross, these two will be dealing most of the damage with Surf, Earthquake, and Rock Slide.

Metagross @ Luminous Moss (Raises Sp.d if hit by Water Move)
Ability: Clear Body
Evs: 4 Hp / 252 Atk / 252 Def
Adamant Nature

• Earthquake (Primary Attack)
• Rock Slide (Coverage)
• Bullet Punch (Priority)
• Agility (Set Up) Replacable

Used at the same time as Latios.

Pelipper @ Leftovers
Ability: Drizzle (Boosts Surf, Eliminates Metagross's Fire weakness)
Evs: 252 Hp / 4 Def / 252 Sp.d
Calm Nature

• Tailwind
• Toxic
• Surf
• Defog

This and Quagsire are supports to the main duo of Metagross and Latios, with Pelipper setting up Rain to boost Surf and lower Metagross's Fire weakness.

Quagsire @ Focus Sash
Ability: Water Absorb (Pairs well with Surf)
Evs: 252 Hp / 252 Def / 4 Sp.d
Impish Nature

• Earthquake
• Acid Spray
• Haze
• Rock Slide

Quagsire is meant to pair with either Latios or Pelipper, due to its immunity/healing from water moves and its similar coverage to Metagross's.

The idea behind this is to deal as much damage with Metagross and Latios while boosting those pokemons power with the other two pokemon.

Comments

Assuming you meant Drizzle and not Damp on Pelipper? Aside from that, I'd be critical of your EV distributions. Quite universally, it's not a good idea to invest in more than three stats total. In most cases, you just want to max the two most important stats, as this lets you isolate roles within your team. You want your Pokemon to be really good at one thing, not just alright at everything.
If you did split your investments, you'd need to be more mindful about it than to simply make quaters of 256. Splitting EVs is usually done because it allows the Pokemon to survive an OHKO or 2HKO from an important threat, which can be found with a calculator like https://pokemonshowdown.com/damagecalc/.

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Thank you, I will change that.

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@Dezerex What kind of doubles? VGC, OU, or something else?
@Fizz Are you sure that's true for doubles and not only singles? At least in VGC19 Moon, Pokemon like 140 HP/108 Def/4 SpA/4 SpD/252 Spe timid Xerneas and 244 HP/156 Def/108 SpD sassy Amoonguss are very common.

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I probably should have clarified this on the actual question, but I put a tag for battle frontier on the question, so this is for any battle frontier where all of these Pokemon, their moves, and their items are available for use.