Your team is really good, there's not much I think I can do to improve it, but I'll try.
Gallade-M
The moveset looks completely fine. Speaking as someone who has used a Mega Gallade Natdex team, and as someone who has seen you play with this team before, the only advise I can give is that you need to use Gallade wisely. Don't try to set up with him unless you have already KOed all opposing Pokemon who outspeed him and don't die to his shadow sneak. Gallade is more frail physically, so try set up on a special attacker. Beware the Mega Pinsir and the Tapu Lele...
Alomomola
Also looks fine, pretty standard physical pivot. Works well with Goodra-H as a defensive core.
Tapu Koko
The additional bulk is good, but I think you should have more speed. 350 is good, but you should be faster so you can outspeed the things that Gallade can't and KO them. I found that an Ev spread of 120 HP, 36 DEF, 136 SPA, and 216 SPE, and Timid nature, works better. It can still OHKO Scizor-M, can still take a +2 Bullet Punch from one, and now has enough speed to outspeed things with 125 Base Speed, like Weavile.
The only OU treats you can't outspeed are Zamazenta and Mega Loppunny. However, due to Tapu Koko's Fairy typing, as well as the bulk of this specific set, you can live a hit from both and proceed to OHKO with Dazzling Gleam:
252 Atk Lopunny-Mega Frustration vs. 120 HP / 36 Def Tapu Koko: 189-223 (60.7 - 71.7%) -- guaranteed 2HKO
136 SpA Choice Specs Tapu Koko Dazzling Gleam vs. 0 HP / 4 SpD Lopunny-Mega: 294-348 (108.4 - 128.4%) -- guaranteed OHKO
+1 252 Def Zamazenta Body Press vs. 120 HP / 36 Def Tapu Koko: 99-117 (31.8 - 37.6%) -- 89.2% chance to 3HKO
136 SpA Choice Specs Tapu Koko Dazzling Gleam vs. 0 HP / 0 SpD Zamazenta: 320-378 (108.8 - 128.5%) -- guaranteed OHKO
Iron Treads
Like Jshreves said, this team would benefit from hazards, and replacing Iron Head with Stealth Rock is a good idea. I know you said Iron Treads can't do anything against Flying types then, but you shouldn't be trying to anyways. Koko should be able to stop most OU Flying types, and if you're trying to sweep with Iron Treads you should eliminate your opponent's flying types first. I think that Stealth Rock support would help this team more than Treads being able to take Flying types.
Ninetales-A
If you don't want Ninetales-A, I have two replacement options for you:
Option 1:
Jumpluff @ Focus Sash
Ability: Chlorophyll
Tera Type: Grass
EVs: 252 HP / 4 Def / 252 Spe
Jolly Nature
- Aromatherapy
- Encore
- U-turn
- Strength Sap/Leech Seed
Jumpluff is the fastest Pokemon possible that is not a Mega that fits your situation. Also frail, but very similar defenses to Ninetales-A. However there is another option...
Illumise (F) @ Focus Sash
Ability: Prankster
Tera Type: Bug
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Aromatherapy
- Encore
- Roost/Thunder Wave
- Light Screen
Before you start saying "There is no way I am going to use Illumise in OU this Hoenn person is tyring to make me lose" Illumise is the ONLY Pokemon who learns Aromatherapy/Heal Bell and Encore that also gets Prankster. Prankster will make it so that Speed is no longer a problem. This little bug is surprisingly bulky, with max Def and prankster Light Screen for special attackers. I mean, look at these calcs:
252 Atk Scizor-Mega Knock Off (97.5 BP) vs. 252 HP / 252+ Def Illumise: 102-121 (30.5 - 36.2%) -- 53.1% chance to 3HKO
252 Atk Urshifu-Rapid-Strike Surging Strikes (3 hits) vs. 252 HP / 252+ Def Illumise on a critical hit: 162-192 (48.5 - 57.4%) -- 99.3% chance to 2HKO
172 Atk Iron Fist Melmetal Double Iron Bash (2 hits) vs. 252 HP / 252+ Def Illumise: 206-246 (61.6 - 73.6%) -- guaranteed 2HKO
Pretty good on the Physical side. Prankster Light Screen will help with the Special defense, so let's look at the Special side:
252 SpA Gholdengo Make It Rain vs. 252 HP / 4 SpD Illumise through Light Screen: 114-134 (34.1 - 40.1%) -- guaranteed 3HKO
252 SpA Zapdos Hurricane vs. 252 HP / 4 SpD Illumise through Light Screen: 199-235 (59.5 - 70.3%) -- guaranteed 2HKO
252 SpA Choice Specs Tapu Koko Thunderbolt vs. 252 HP / 4 SpD Illumise in Electric Terrain through Light Screen: 131-155 (39.2 - 46.4%) -- guaranteed 3HKO
252 SpA Choice Specs Kyurem Draco Meteor vs. 252 HP / 4 SpD Illumise through Light Screen: 181-213 (54.1 - 63.7%) -- guaranteed 2HKO This thing survives a FEAKING SPECS DRACO METEOR from the one of the highest Spa Dragon types in the tier
This Hoenn bug type is perfect for the needs of your team. As an added bonus, because she is so low tier, most OU players have no idea what to expect from this Pokémon.
In summary, your team looks pretty good, just a few tweaks here and there are all that's needed. Besides replacing Ninetales-A. That thing has got to go. Hope I helped.
