From what I understand, this team is one that you've already bred in-game so I'll try to make some suggestions without changing the team members.
I would like to second
Choice Scarf > Choice Specs on Hydreigon as it allows for you to more effectively check Latis. I would also like to suggest
Fire Blast > Flamethrower on Hydreigon, because even though Fire Blast's accuracy is imperfect - there's quite a noticeable power difference, using a scarfed Magnezone as demonstration.
252+ SpA Hydreigon Flamethrower vs. 0 HP / 0 SpD Magnezone: 230-272 (81.8 - 96.7%) -- guaranteed 2HKO
Vs.
252+ SpA Hydreigon Fire Blast vs. 0 HP / 0 SpD Magnezone: 280-330 (99.6 - 117.4%) -- 93.8% chance to OHKO
I would also suggest that you run
U-turn > Roost on Hydreigon, as being locked into Roost can easily turn it into set-up fodder while U-turn allows for you to predict your opponent switching out and effectively creates the same result as a double switch with minimal risk involved.
I would also second
Life Orb > Wise Glasses on Gengar, and I would also suggest a few possible changes that you would take for its moveset. Energy Ball's extra power, even on a glass cannon, is usually considered inferior when Gengar gets
Giga Drain via TM. Dazzling Gleam thereotically hits Dark-types, but it's not really worth it and to be honest, pretty weak. The only real relevant dark-type it hits is Mega Sableye, which is 2HKO'd by an Life Orb Shadow Ball anyways. In fact, the rare Umbreon isn't even 2HKO'd by it. Tyranitar is hit harder by Focus Blast and Bisharp definitely is, both of which are very common Dark-Types. Therefore, I suggest
Focus Blast > Dazzling Gleam.
Also, it was previously suggested that you run
Water Pulse > Scald by
Stardust Dragon, but I don't believe the power boost is worth it. If you're going for power, then use Hydro Pump. Scald is only marginally weaker, and the 30% chance to burn is actually quite absurd compared to Water Pulse's paltry 10% chance to confuse. Essentially,
Scald > Water Pulse.
I would suggest that you evolve Scyther to make yourself less weak to Latis, but HP Fire has been on the rise lately so...
For EV spread changes, I would suggest that you move the 4 HP in Scyther to one of its defenses - this will reduce the amount of damage it takes from Stealth Rock provided its IVs give it an odd amount of HP naturally, and will allow for it to switch into Stealth Rocks twice before fainting. I also would advise against using U-turn on a set-up sweeper, so I would suggest that you put on either
Superpower or
Knock Off in its place. Superpower prevents Scyther from being hard walled by some steel-types, while Knock Off is a general safety net move. If you want to play Scyther as a bulkier set-up sweeper, or allow for it to more reliably check a Lati, then you could run
Roost > Bug Bite for the recovery while still retaining Superpower for coverage.
For Steelix, I would personally change its set to have Dragon Tail or Toxic over Stone Edge on a team I built but your team doesn't need to be any more Talonflame weak, so I would advise against changing its moveset.
For Gallade, I would suggest
Knock Off > Destiny Bond. Much of what would try to revenge kill Gallade would outspeed it before you manage to pull a Destiny Bond, and Knock Off rounds off Gallade's coverage so that it doesn't get walled by Psychic-types, and lets you at least touch a weakened Mega Sableye. I can see Mega Sableye being a big issue to your team, so while Dragon Tail on Steelix might be beneficial for preventing it from sweeping you, it's usage has somewhat declined, whereas Talonflame is still rather common.
Oh, and sorry to burst your bubble, but winning 60-65% of your battles is not considered particularly impressive on the ladder. Many people in the lower ladder will build around their favorites, but they have a tendency to not have much more than a basic grasp of game mechanics. The majority of people playing on the ladder are on lower ladder, so that would make anybody decent's GXE about 70% provided they don't get haxed to death by their opponents multiple times through multiple matches. Also saying this in case you don't know, if you click on your name and see your profile for your ranking, the GXE is an estimate based off of your win/loss ratio to determine your chance of winning against a random opponent on the ladder.