Question

This is for Leaf Green, Kanto Pokemon only, and Gen 3 (so Physical attacks are any moves of the types Normal, Fighting, Poison, Ground, Flying, Bug, Rock, Ghost or Steel; Special attacks are those having the Fire, Water, Electric, Grass, Ice, Psychic, Dragon or Dark type.)

This is the team so far:
Charizard: Flamethrower, SunnyDay, BrickBreak, Solarbeam (Charcoal)
Exeggutor: Psychic, GigaDrain, Toxic, DoubleTeam (Leftovers)
Steelix: Crunch, Double-Edge, Earthquake, IronTail (Shell Bell)
Gengar: Shadow Ball, Psychic, NightShade, ConfuseRay (Kings Rock)
Zapdos: Thunderbolt, SteelWing, ArialAce, DoubleTeam (magnet)
Laprus: Icebeam, Surf, PerishSong, Hail (nevermelt ice)

Answer 1

If you were interested in playing doubles then you will need to find a way to incorporate a tank or wall. Basically get a high hp and defense pokemon (snorlax, blissey, giratina) give it leftovers. It makes it exceeding hard to ko, and blissey can learn a move that causes all attacks to be directed at it, allowing your other pokemon to deal out the damage scot free.