Dedicated leads are risky to use because of Team Preview.
Choice Band Scizor should use a bulky spread because it can take hits more easily this way: 248 HP/252 Atk/8 SDef. Your current EV spread is better off for the offensive Swords Dance variant.
Landorus is illegal until Poke Bank. You'll need to make do with Gliscor, who's your best bet for a Ground physical wall until Poke Bank is released:
-Earthquake
-Toxic
-Protect/Roost
-Substitute/Taunt
Nature: Impish
EVs: 244 HP/252 Def/12 Spe
Item: Toxic Orb
Ability: Poison Heal
or
-Earthquake
-U-turn
-Taunt
-Roost/Knock Off
Nature: Impish
EVs: 244 HP/48 Def/216 Spe
Item: Toxic Orb
Ability: Poison Heal
or
-Substitute
-Baton Pass
-Earthquake
-Taunt/Swords Dance/Agility/Rock Polish
Nature: Impish
EVs: 244 HP/48 Def/216 Spe
Item: Toxic Orb
Ability: Poison Heal
Heliolisk needs a reliable Electric STAB, since Volt Switch will force it to leave battle every time it uses it:
-Thunderbolt
-Volt Switch/U-turn
-Focus Blast
-Hidden Power (Ice)/Grass Knot
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb/Choice Specs
Ability: Dry Skin
Assault Vest Tyranitar should look like this, since I don't think Ice Fang is doing much outside of hitting Dragonite and Salamence, who are already hit hard enough by Stone Edge:
-Crunch
-Pursuit
-Stone Edge
-Fire Blast
Nature: Brave/Sassy
EVs: 252 HP/252 Atk/4 SDef or 252 HP/4 Atk/252 SDef
Item: Assault Vest
Ability: Sand Stream
Aegislash should use an Adamant nature with 252 HP/252 Atk/4 Def. I don't think you understand how Stance Change works:
Not exactly. Physical Aegislash are commonly seen using Adamant natures with 252 HP/252 Atk/4 Def. While this seems pointless, when Stance Change activates, the new 150 base Attack of Aegislash's Blade Forme will use the 252 Attack EVs. Mixed Aegislash are occasionally seen as well.
At level 100, the maximum Attack of Shield Forme Aegislash is 218. In Blade Forme, this becomes 438 when the Attack and Defense switch.
Only the base stats are swapped, not the EVs, IVs, Nature, etc. So, you'd definitely want to invest plenty of EVs into the offensive stats.
Half this team is vulnerable to Ground Pokemon, so something that can eliminate them like Trevenant, Gourgeist and Greninja are good fits to the team.
Trevenant:
-Wood Hammer/Horn Leech
-Earthquake/Rock Slide
-Will-o-Wisp
-Rest
Nature: Impish
EVs: 252 HP/176 Def/80 Spe
Item: Leftovers/Lum Berry
Ability: Natural Cure/Harvest
or
-Substitute
-Leech Seed
-Will-o-Wisp
-Phantom Force
Nature: Impish
EVs: 252 HP/176 Def/80 Spe
Item: Sitrus Berry
Ability: Harvest
Gourgeist:
-Will-o-Wisp
-Leech Seed
-Protect/Pain Split
-Seed Bomb/Shadow Sneak
Nature: Impish
EVs: 252 HP/4 Atk/252 SDef
Item: Leftovers
Ability: Frisk
Greninja:
-Hydro Pump/Surf
-Dark Pulse
-Ice Beam
-U-turn/Grass Knot//Hidden Power (Fire)
Nature: Hasty/Timid
EVs: 4 Atk/252 SAtk/252 Spe
Item: Life Orb
Ability: Protean
or
-Spikes
-Hydro Pump/Surf
-Dark Pulse/Ice Beam
-Hidden Power (Fire)
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb/Focus Sash
Since Scizor and Heliolisk have a tendency to switch around a lot, consider a Rapid Spinner like Excadrill or Starmie:
Excadrill:
-Earthquake
-Rock Slide
-Rapid Spin
-Shadow Claw/Swords Dance
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Life Orb/Assault Vest/Air Balloon
Ability: Sand Rush/Mold Breaker
Starmie:
-Hydro Pump/Surf
-Thunderbolt/Psyshock
-Ice Beam
-Rapid Spin
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Leftovers/Life Orb
Ability: Natural Cure
or
-Scald
-Rapid Spin
-Psyshock/Ice Beam/Thunderbolt
-Recover
Nature: Timid
EVs: 248 HP/32 Def/4 SAtk/224 Spe
Item: Leftovers
Ability: Natural Cure