Rate my Battle tower Doubles team

[Sceptile Leaf Blade]

After getting over 105 wins in a row at the singles Battle tower, I decided to try double battles. It seems to be working from practice, but I still need a 4th member.

Metagross @ Choice Band
Adamant nature
stats: 405 Atk, 322 HP, 322 Def, 170 Speed, 189 Sp.Atk, 198 Sp.Def
-Meteor Mash
-Earthquake
-Rock Slide
-Shadow Ball

Latios @ Shell Bell
Naive nature
stats: 297 HP, 211 Atk, 179 Def, 352 Sp.Atk, 213 Sp.Def, 320 Speed
-Psychic
-Dragon Claw
-Thunderbolt
-Surf

Salamence @ Lum Berry
Adamant nature
Stats: 328 HP, 405 Atk, 188 Def, 214 Sp.Atk, 191 Sp.Def, 299 Speed
-Aerial Ace
-Dragon Dance (Don't want to replace as I can't put it back on it again, and the IV's of this Salamence are amazing)
-Rock Slide
-Earthquake

Starmie @ Brightpowder
Modest nature
Natural Cure
Stats: 238 HP, 162 Atk, 181 Def, 328 Sp.Atk, 183 Sp.Def, 328 Speed
-Surf
-Ice Beam
-Thunderbolt
-Psychic

CB-Metagross seems to be evil in doubles from what I have seen so far. CB Earthquake is the main cause, which hits both foes for full damage (as opposed to Rock Slide or Surf that only hit half damage), and tends to OHKO anything weak to hit not named Steelix or Regirock (it OHKO's Tyranitar and Metagross, while they do about 50% back to my Metagross with EQ), and tends to OHKO any not bulky pokémon not resisting it like Glalie, Starmie, and so on. It tends to put bulkier pokémon like Milotic, Vaporeon, Blissey, Slowbro, and Blastoise in the red after a single hit. Combined with Latios this is quite extreme. Latios is immune to EQ, and can either OHKO a foe if both foes are fragile (so that the switch in gets pounded by EQ for 3 kills in one turn), or weaken a bulkier pokémon so that it then gets KO'd by the oncoming Earthquake.

Salamence is also immune to Earthquake and functions similar to Latios in providing covering fire. It can use Earthquake itself when partnered with Latios.

Starmie is the main pokémon I want replacement for, it is not immune to Earthquake (so it dies whenever Metagross quakes) and provides the same type coverage as Latios, just with slightly less Sp.Atk. I was thinking about perhaps Gyarados, but not sure if it is a pokémon this team needs, and Gyarados lacks type coverage.

 

[Emeraldfan]

Yeez dude, you've got some flawless IV there...
Anyway, as for a replacement for Starmie. You obviously want it to be fast, and somewhat hard hitting. I don't know what games you've got acces to, but if you can, I suppose a Gengar would fit.
It's both faster and harder hitting than Starmie, and has Levitate.

Gengar
Timid
x / x / x / 31 / x / 31
42 HP / 252 Sp Atk / 216 Speed
~ Psychic
~ Thunderbolt
~ Ice Punch
~ Fire Punch

The IV's I listed are a minimum, you're always free to get some other flawless ones, but these are most needed. Timid + 31 Speed IV + 216 Speed gets you at 341 Speed, just below its max, 350, but it's all it needs. It can now outspeed everything but these:
394 jolteon (4)
359 jolteon (1), crobat (3,4)
There's no way you can outspeed these, so don't even try. Max Sp. Atk for obvious reasons, rest in HP for *cough* bulk...

I couldn't really find anything wrong with this team. The type coverage could've been better, but this team relies on hard hitting to win the game, and for that it's perfectly suited.

Also, I'm assuming Latios has the 6 / 252 / 252 spread? If not, try to hit 340 Speed, if you can. Otherwise try 339, 330 or 328. Those numbers allow you to outspeed just a few more threats.

 

[Sceptile Leaf Blade]

Yeah Latios has 6 HP, 252 Sp.Atk, and 252 Speed EVs. Unfortunately I don't have access to a second GBA so I can't get Gengar from my Firered version over. I definitely need something immune to Earthquake as I'm also trying out Palace doubles now, and I need to ditch Metagross there as it keeps on getting destroyed by Salamence. I'll try Gyarados, could be fun.

I got really lucky for the IV's with an Adamant Ditto I caught that had a 31 Attack IV. It is extremely useful to breed for physical sweepers. After a couple of hundred eggs I got very lucky with that Bagon as well, flawless attack, flawless speed, and all defensive IV's over 25.

 

[Emeraldfan]

Too bad you can't get Gengar, I really think that it'd be a great addition...
Anyway what I can do now is list Flying and Levitating Pokémon, you should probably make your pick from there. Keep in mind that this list consists of both offensive and defensive Pokémon.
Weezing
Flygon
Claydol
Crobat
Dodrio
Gyarados
Xatu
Gligar
Skarmory
Swellow

The problem however is that most of these Pokémon serve best as a physical sweeper, but what you kinda need is a special sweeper. With that in mind, Flygon seems the best choice, since it can at least go mixed...
Then again, that really increases your Ice (and Starmie) weakness...

 

[Sceptile Leaf Blade]

I guess Gengar also dies in one hit by Starmies Psychic but w/e. Starmie still dies in one hit by Latios' Thunderbolt and also in one hit by either Shadow Ball or Earthquake coming from Metagross.

Weezing and Claydol could go special, but are too defensively oriented for doubles. Walling is tougher with two foes piling on you and has not much point if the partner has to pull all the offensive weight and my battles generally last 3 or 4 turns taking everything they have down. Flygon is quite a good tip, could also get me some more additional type coverage whilst Gyarados simply is another EQ. I'll go with something like this:

Flygon @ Brightpowder
Naive nature
252 Speed, 200 Sp.Atk, 56 Atk
-Earthquake (because STAB EQ in doubles just works)
-Fire Blast
-Crunch
-Dragon Claw

 

[Emeraldfan]

Max Speed is indeed quite useful. As of now, you're only outsped by this:
394 jolteon (4)
359 jolteon (1), crobat (3,4)
339 dugtrio (1,2,3,4), sceptile (1,2,4)
338 aerodactyl (1,2)
329 starmie (3,4), raikou

If you were running a Speed neutral nature, you would be outsped by the following:
394 jolteon (4)
359 jolteon (1), crobat (3,4)
339 dugtrio (1,2,3,4), sceptile (1,2,4)
338 aerodactyl (1,2)
329 starmie (3,4), raikou
327 gengar (1)
319 gengar (2,3,4,5), espeon (2,3,4), tauros (1)
318 sceptile (3)
316 electrode (2,3,4)
309 electabuzz (3), manectric (1,2,3,4)
306 kangaskhan (3)
299 charizard, dodrio, entei, fearow, flygon, ninetales, raichu, salamence, typhlosion, ?zapdos?

Gengar (4) has Ice Punch and obviously the Dragon types could be carrying Dragon type moves.
I'm not really sure what you're trying to get at with 56 Atk though, any specific reason for that?
Other than that the set is fine, I suppose Crunch works fine > Rock Slide since the latter halves in power and because you're more specially orientated.

 

[Sceptile Leaf Blade]

No real reason for those EV's, I don't really know what would be a favourable EV spread for mixed Flygon.

I'm also getting another Hardy Flygon for the Palace doubles as Hardy attacks more than Naive, and Palace holds different AI pokémon from the rest of the facilities (I've seen one of the AI's use a lvl 100 Weedle there, and another use a lvl 100 Metapod which only knew Harden).