I chose Alakazam to be on this team over Starmie because he makes one of the best leads in the entire game. It comes down to Alakazam or Exeggutor and with how the meta shifted from being the best lead with the easiest time inflicting sleep it shifted to who actually got inflicted with sleep and not just how early in the game you inflict it and I feel like Alakazam takes the lead role well to help counter those sleep leads better while giving me a fast Twave lead. Psychic is STAB and Seismic Toss to help keep my PP high on Psychic when I need it for those stall wars on Chansey. I find Alakazam nearly to be a staple on any team and only slightly comes preferred to Starmie for me.
Best sleeper in the game while offering that crucial resistance to Psychic and having a solid bulk to both physical and special attacks. Mega Drain was solely chosen to keep him alive longer to do some more damage. Explosion is self explantory as it helps pick off the likes of Chansey, Alakazam, and other annoyances in the metagame that can otherwise wall my late game sweepers such as Tauros and Zapdos. I do use Exeggutor as a lead at times too.
Lets start off discussing Surf. I use it to help counter Golem/Ryhdon to help clear a path for Zapdos to come in and begin his sweep. I hide my Zapdos till I see a Golem or Ryhdon and clear them with Surf or the likes of another pokemon on my team. Whether that is self destruct, surf, or exeggutor. But often they wont stick in on my Exeggutor and will only switch out so I opted to choose Surf to help make a solid core with Zapdos because Zapdos is so powerful I feel he is worth using. Self destruct because having 2 pokemon who can suicide to remove any potential threat is nice to have and snorlax does that the best, pretty much instant KO on whatever he explodes on. Body slam for that para hax and STAB, his primary source of damage and primary attack to use. Earthquake so i cant be wall'd by gengar and felt i wouldnt use the likes of hyper beam as much as id use earthquake.
Opted for Ice Beam over blizzard to help keep golem and ryhdon in check with thunderbolt to give me better coverage ontopnof keeping pokemon like starmie in check and not allow them to sit in on my chansey to freeze it. Soft boiled to help shrug off damage and keeps me alive to keep spreqding those ice beams or twaves even longer. Not much else to say about chansey.
My late game sweeper when any check or counter has been solely taken care of or weakened to the point it is no longer a cause of concern. Body slam for STAB and para hax while hyper beam acts as a really solid finisher so i dont get stuck charging for a turn. The least used move of the set but has its needed niches and wins battles, for sure. Earthquake to help keep gengar from walling me similar to that of snorlax and gives me a little bit more coverage and blizzard to help my odds at freezing a pokemon outside of just attempting so with a chansey if I lose her by some chance. It also helps with golem/ryhdon as well and really paves way for zapdos to come in and finish off what tauros couldnt if I had to for some reason bring him in earlier than Id have liked to.
Agillity to help ignore the effects of a paralyze if I manage to get inflicted with it and keep me a speed tier ahead of the opponents team to provide me with that opportunity to sweep with either drill peck or thunderbolt. Both STAB and give me a nice variety. Twave to give me a 3rd user of this move giving me plenty of options from start to finish to keep my opponents team undee parahax through and through. Zapdos usually comes in late game to sweep off the remainder of the team with ease after its checks and counters are dealt with entirely, primarly speaking of golem and rhydon. Surf snorlax creates a good core with zapdos to make sure the sweep happens.