I don't think I have anything revolutionary to say, so I'll keep it brief. I have no remorse about putting seven Pokemon in three different S Tiers. This is the best way to analyze the tier.

Mr. Mime isn't really broken or anything, but there is basically no reason not to use it. Its defensive profile isn't the most inspiring, but its Speed tier, coverage, and access to Thunder Wave make it pretty difficult to exploit. It's also the primary answer to itself, so there's that motivating you to use it too. Acceptable lead choice.

Venomoth is the best sleeper in the tier. Like Mr. Mime, access to a paralysis-inducing move and a good Speed tier keep it from being too exploitable. It's not the most offensively threatening thing, but Psychic can somehow bullshit its way through basically the entire tier with critical hits and Special drops. It's also surprisingly decent into Electrode.

Clefable can beat basically the entire tier one-on-one once it has protection from Sleep Clause. Excellent utility with Thunder Wave and Sing as well. Only more droppable than Mr. Mime and Venomoth because the Speed tier can be a bit of a liability.
I've been forgoing Body Slam, which seems to be the wave, and I honestly don't really ever find myself missing it. Also, don't feel like you have to click Thunder Wave all the time, especially if you have a fast team. Damage is often more important then Paralysis in NU and Clefable's Hyper Beam is stupid strong.

Raticate is somehow more of the NU Tauros than any of Kangaskhan, Dodrio, or Persian is the UU Tauros. Its combination of traits (namely Speed, Attack, typing, and Body Slam) make it the best physical attacker and revenge killer in the tier. Super Fang is neat, but only really needed for a few team structures. With good positioning and/or proper trading, this Pokemon can be exceptionally rewarding.

I don't really like lead Charizard, but it is arguably the best lead. It matches up well into every Fire-type Pokemon and only really loses to slow stuff that has to contend with Venomoth. It's arguably even better when outside the lead slot, especially with its legitimately wide set variety. Swords Dance can and will completely steal games and combos well with Explosion users. Four attacks sets can sweep weakened teams, notably through Raticate. Counter can pick up a lot of damage. Fire Spin sucks but can do work occasionally. Charizard is an extremely dangerous Pokemon that I honestly think could use more respect and exploration. Fairly droppable, but way scarier than stuff like Blastoise if played well.

Kind of like Clefable, in a roundabout sense. It can't one-versus-one as many things nearly as well, but it stuffs Fires and Seadra while having an OHKO on Golem to prevent it from just booming on you for free. This Pokemon also legitimately only needs like two moves, so you can just go free range with whatever after Surf and Seismic Toss: Counter, Blizzard, Hyper Beam, Body Slam, Earthquake, Rest, Substitute apparently, etc. Does Hydro Pump get any rolls? Never checked.

Broken Pokemon. Has some checks and needs to evade being paralyzed, but it just mops up teams. Best sweeper by a mile and single-handedly keeps Charizard from being a top three Pokemon. The only reason it's this low is because it's the only Pokemon thus far that can really get into trouble in a bad matchup, so, while it can go on many teams, it can't really be an automatic addition. Depending on how you rank Pokemon though, I can see an argument for Electrode being as high as #1 or #2.
You can run Thunder on this. Hyper Beam doesn't hit much. Substitute is also neat.

Seadra can be dangerous, especially after setting up, but it's kind of hard, especially with how teams tend to look now. Blastoise is better because it does better into Blastoise. Seadra does especially well into bad teams while still being decent into good ones.

Walls Electrode. Earthquake and Rock Slide are hard to switch into most of the time and Explosion is good. The tier is fairly hostile to it, but it's the best Ground-type Pokemon if your team needs one and it can beat Fire-type Pokemon if it can avoid Burns. It also walls Fearow and can catch Raticate (or Clefable) Hyper Beam, which are neat traits.

Lots of good Pokemon give Moltres trouble, but it pressures a lot of the
really good ones. It's held back mainly by being not the easiest to fit on teams, but it can do work on the right builds or with a good matchup.
I would draw the NU cutoff here if that was relevant.

Fine into Mr. Mime and Clefable and alright into Electrode. I think Charizard tends to be worth more though and fitting both is not always the best move. While Charizard and Moltres have higher ceilings, there's an argument for Arcanine being more consistent or less costly in the builder. In other words, you'll seldom
need Arcanine in a game but similarly seldom
regret carrying it. It and
maybe Ninetales are the only Pokemon with a serious argument to be above the cutoff that I didn't already place there.
I do understand that Arcanine, Charizard, and Moltres all function pretty differently, but that doesn't change the fact that running multiple causes you to not run other better Pokemon that are simply more threatening on a game-to-game basis. Also Seadra can become a threat with enough Fire-type Pokemon on your team.

Similar state as Arcanine. Confuse Ray can be brutal. I lean towards Arcanine being better, mainly due to its higher usage biasing me, but Ninetales could have enough things going for it instead, assuming someone bothered to check.

Kabutops isn't super easy to fit on like any team and loses to a ton of stuff, but it is a really solid counter-team option to meet some builds.

Fearow is not as good as it feels like it should be. It wants Body Slam and the Flying typing is actually loathsome in this tier. Still really strong though, and it's faster than Raticate. Not terrible.

Mostly used for counter-teaming. Beats Raticate lacking Super Fang and its Hypnosis and/or weak Explosion can combo into some things, like Seadra Agility or Charizard Swords Dance or just Raticate.

Teams don't really need two Clefable. Its poor Special makes it incapable of relying on Blizzard + Thunderbolt, unlike Clefable, so it is way more linear. Its Speed is also a massive liability, especially considering you are almost certainly running it with Clefable already. Decent Counter. Very mediocre overall.

I have not yet identified the reason to use this Pokemon. I'm sorry.

Awful in practical terms. Slow, weak, unreliable. Kind of beats Mr. Mime, I guess, and has some utility moves. There is so little room for this Pokemon on a normal team.

Just awful. Not unviable, I guess, but it actually dies to like every hit in the game barring Thunderbolt. It's not even that offensively potent, especially with such a mediocre Speed.

Maybe decent, but hard to justify over faster and more reliable Pokemon. I have some faith, but it is somehow always critically hit.

Good Speed tier.

Dangerous, but outsped by everything it threatens.

Good Speed tier.

Psychic-types are usually decent and this one has utility moves.

Psychic-types are usually decent and this one has the magic Speed stat number.