So this is my GSC team I made. Most sets are copypasta from Smogon but I have made some small alterations to the Smogon sets as I saw fit. As you already know EVs and Natures didn’t exist then and the choice of held items was rather limited so most of it is Leftovers.
Gengar @ Leftovers
-Shadow Ball / Hypnosis / Explosion
The idea is to hit anything I could face in the lead hard. T-Bolt and Ice Punch give that famed BoltBeam coverage and Fire Punch puts serious dents in Steelix, Forry, Skarmory, and etc Steels. In the last slot I’m torn between the above mentioned moves. Although Ghost is Physical in this Gen, Shadow Ball can put a hurting on Alakazam, who is used a lot more in GSC than in the current metagame. Explosion is for Blissey mostly and would let Gengar go out with a bang after it has surpassed its usefulness. Hypnosis helps to counter the every so common SleepTalkers.
Charizard @ Leftovers
BellyZard is the main sweeper of this team. Since Stealth Rock doesn’t exist yet, Charizard can shine in GSC. Its attacking moves have pretty good coverage. Fire Blast takes care of Steels or anything else with high Defense that could wall its physical moves, like Skarmory.
Wobbuffet @ Miracle Berry
Not much to say about Wobb but it’s lack of Encore and Shadow Tag don’t make it broken like it is now. Wobb still gets the job done and it will most likely be taking at least one of my opponent’s Pokemon down, and might be able to take down a second with Destiny Bond. If I suspect a status abuser, I’ll use Safeguard. Miracle Berry is there to get rid of the initial status since Wobb won’t be fast enough to set up Safeguard before getting hit.
Alakazam @ Focus Band
Charizard is the Phsyical sweeper and Alakazam is the Special sweeper. Not many thing like switching in on a STAB Psychic and having to take a second hit before they can attack. In fact, most things not Steel, Psychic, Dark type, or Blissey are KO’d by that. The fact that Calm Mind doesn’t exist yet hampers Zam’s sweeping potential but T-Wave picks up the slack by making sure the few things that are faster than Zam (like Electrode, Jolteon, Aero) are no longer a threat if it catches then on the switch and paralysis helps the rest of the team out. Fire Punch takes care of Steels and can at least do some damage to Darks. Recover is still useful since Calm Mind and Nasty Plot don’t exist yet meaning Zam’s okay Special Defense won’t be penetrated by boosted Special sweepers and it can stall them out.
Foretress @ Mint Berry
Standard Spiking Forry. Rest and Mint Berry for maximum longetivity so it can get Spikes in and wall Physical moves. Rapid Spin is to get rid of opposing Spikes and Explosion is when Forry’s finished doing its job.
Blissey @ Leftovers
Another standard set. Toxic is to spread the status around. Softboiled is to stall out Special attackers. Heal Bell gets rid of any status on my team and Ice Beam provides some offense and puts a nice dent in Dragonite.