Let me break down Clodsire's possible niche in OU:
- If I want something with Unaware, I would first reach for Dondozo to wall physical setup sweepers and maybe consider Skeledirge as a backup option.
- If I want something with Water Absorb, I would strongly consider Ogerpon-Wellspring or Volcanion to provide offensive momentum that Clodsire can never provide. If I want more of a defensive presence, I could also consider Gastrodon or Vaporeon.
- If I want something defensively oriented with Spikes, I can use Ting-Lu, Skarmory, Gliscor, or even Garchomp.
- If I want something with Toxic Spikes, I can go to the Church of Toxapex and have even more bulk while mitigating setup opportunities with Haze.
- If I want to derp around, I can use Quagsire just as easily and do the same thing (and also use the same abilities).
Blissey and Chansey will always have a place on a stall team because of their ability to wall the biggest and baddest OU special attackers to the moon and back. Clodsire cannot claim that same luxury. It might have a very narrow niche in OU, but I do not put something with as narrow of a niche in that same category.
1. Clodsire is a specially defensive unaware mon. This means it can wall pokemon Dondozo can never dream of like Raging Bolt or Darkrai (sp.defensive dozo is a set yes, but its a lot worse then physically defensive as it loses to pokemon such as Kingambit and Roaring Moon a lot easier). Skeledirge is more of an offensive unaware mon, using unaware to switch into targets and start boosting its special attack. Clodsire is a vastly different mon from these two, so you wouldn't even consider it and dozo in the same scenarios.
2. Waterpon and Volcanion utilise Water Absorb more offensively. So idt comparing them and clodsire is fair. Clodsire is also far, far better then either gastrodon or vaporeon. Vaporeon is a do nothing blob that pisses into anything that does not care about scald (tera water garg, cm clefable, waterpon, raging bolt, sub prim, wake, enam, cm valiant) and makes no progress outside of that. Gastrodon is a lot less threatening honestly, as if a pokemon doesn't care about one of ep+surf or ep+ice beam, it will set up on it. Clodsire at least has toxic/p-jab+e-quake which aside from gliscor, balloon ghold and corviknight, is deceptively threatening.
3. Notice how only two of those (skarmory and gliscor) has recovery? And skarmory takes on the physical side of things. It is also similarly passive into a lot of stuff that doesn't care about bp (gholdengo, dragapult, sinistcha, valiant, enam, moth, hatt, molt, zapdos). Ting lu can run rest sets, but those are much more passive. Gliscor is the only thing that competes in its role of specially defensive spike settter with recovery, but gliscor is A+ for a reason.
4. T-spikes is rare on Clodsire, and Toxapex at times drops it for other moves like surf or baneful bunker. Clodsire also has unaware, or if you are running water absorb, either amnesia or haze of its own.
5. Quagsire is much, much inferior then clodsire, and its not even close. The only reason you are using quagsire is as a alternative physically defensive unaware mon to Dondozo that has access to instant recovery, toxic, and spikes. That is the only success it has had. So not remotely comparable to clodsire. Quagsire also never uses water absorb.
In reference to Blissey and Chansey, 1. Clodsire is still VERY good on stall, its A rank in the stall VR for a reason due to its ability to help blissey with walling special threats. 2. Clodsire can fit onto Balance teams, something which Blissey can't really do. I would say Clodsire is in fact, comparable to many of the B ranks.
We have:
Araquanid: Premier setter for one playstyle, so limited in its role but very good at that role.
Hawlucha: Incredible abuser on one decent playstyle and a few nicher playstyles.
Hoopa-Unbound: Absolutely decimates one playstyle while having some value against other playstyles.
Keldeo: Decent mon all around. Not much to expand on here.
Manaphy: Similar to Hoopa-Unbound in its ability to destroy one playstyle and can do something against other playstyles.
Meowscarada: Honestly, prob would drop this, but decent speed control.
Ogerpon-Cornerstone: Really great against fatter playstyles, while potentially helping a lot against faster playstyles.
Okidogi: Counters a ton of top meta mons (like zama, darkrai, valiant, gambit).
Ribombee: okay, this should def drop. Outclassed by araquanid entirely, and struggles to get up webs/do anything afterwards.
Serperior: Can be quite an annoying disruptive mon that has the potential to sweep.
Slither Wing: Bit of an anti meta mon (maybe I'm wrong on this) but has nice defensive utility against quite a few top tier mons and can revenge kill a lot of things.
Skarmory: A bit passive in regards to some other mons, but is very sturdy on the physical side and can spit up spikes.
Torkoal: Worse sun setter then ninetales, but does pack a lot of utility with rocks and spin.
Tornadus Therian: Bit unreliable with its moves, but a very fast pivot with knock and good coverage.
Toxapex: Bit passive into poison and steel types, but can do really well if they are removed by walling a ton of the metagame and spreading poison everywhere.
Volcanion: Amazing fat destroyer that can trade well with offense.
Looking at Clodsire, I'd say its on par with these mons. Clodsire is a good pick on Balance and Stall teams, with its ability to shut down a large portion of the metagame while making progress with spikes. I don't think it should drop at all and is fine right where it is at B.