For Metagross, Go for Adamant. Max EV in Atk and maybe Spd if you want to keep Agility.
Metagross @ Life Orb (or something else)
Adamant. EVs: 6 HP, 252 Atk, 252 Spd
For Scizor, if you give it Choice Band, then you can't use Swords Dance or Roost because you'll be stuck with it. Instead of Choice Band, give it... Iron Plate or something.
Scizor @ Iron Plate
Adamant. EVs: 252 HP, 252 Atk, 6 Sp. Def
Gengar @ Focus Sash
Modest. EVs: 6 HP, 252 Sp. Atk, 252 Spd
Starmie @ Choice Specs
Timid. EVs: 6 HP, 252 Sp. Atk, 252 Spd
These 4 should be plenty.
I am a glitcher, not a cheater. I do not alter game codes, but use what's given to get what I want.
As an RNGer, I can RNG any breedable and encounter Pokemon to any nature, ability, IV spread, shininess, etc. For those in dire need of a certain Pokemon, I might accept trade requests for any breedable Pokemon to full specifics (DW Abilities limited, ask for availability) in return for 1 Rare Candy.