not gonna comment on the other mons cus i think everything that cud be covered has been covered on them, i love xurkitree but yeah its pretty obnoxious and i wouldnt mind seeing it go. making this post cause i think the pro zarude ban discourse is flimsy at best. there are different arguments that are being responded to here but they all kinda culminate together anyhow.
- Zarude can employ a multitude of sets including Choice Scarf, Jungle Healing with Heavy Duty Boots, and Choice Band. Outside of Power Whip and Darkest Lariat and U-turn on Choice sets, it can run a variety of moves such as Close Combat, Iron Tail, Rock Slide, and Bulk Up on Jungle Healing sets that all allow it to take on a different set of checks and counters. Its excellent stats and movepool has limited checks to bulky Fairy-types and Cobalion. Without Cobalion, teams are forced to shift defensively to handle Zarude, making it an arguably restricting presence in RU.
the variety of sets that zarude can run seems overwhelming in theory but in practice, and as someone who spammed scarf zarude since it dropped into the tier, the boots jungle healing set (specifically with uturn because bulk up is not actually that useful, but ill get into that later), outshines all the others by a pretty significant margin. this is because one of the biggest aspects of what makes zarude so great is its ability to stop bulky waters like suicune and seismitoad. without jungle healing you really lose out on how effective you are at that role, because between being forced to take sr damage if its up (and it's not really hard to do that considering the rockers are all pretty amazing in their own right thanks to the metagame being kind enough for them that keeping them up is pretty easy to do for most teams) and risking being completely cucked by scald, not running jungle healing is a big hinderance to how it performs defensively. u-turn is way better than bulk up because its way more optimal to take advantage of how much you force out by keeping momentum than having a move that is reserved for breaking, which is also kinda hard to accomplish with the amount of counterplay you have to it.
as far as the other options go, i think iron tail is honestly the only one worth considering because of how amazing togekiss and weezing-g are in this meta. close combat is nice for cobalion but it's not like you're not being directly punished for that either if you're running rocky helmet, and again, any chip on zarude is incredibly detrimental if you're not running jungle healing. rock slide is for like, talonflame i guess? which is cool and all but not really that important either. really, what i'm getting at here more or less is that zarude, while having a great movepool, shines in such a way that using it for anything that isn't a pivot that lasts long and grabs momentum consistently is not a zarude that's being used at its best. is zarude a bad scarfer? not necessarily. is zarude a bad wallbreaker? not really, either. the main thing here is that, unlike the jungle healing set, these roles are definitely not unique to zarude, because we have a plethora of great scarfers and wallbreakers to the point where you can still achieve the same goals that you would be with other mons that you are with jungle healing uturn.
with that in mind, the amount of counterplay beyond cobalion that you have for it is not really that constraining. as mentioned before, weezing-g and togekiss are both really good for providing defensive backbone for teams and aren't completely specialized just for zarude. there are less sound switchins that can still pivot in on it and serve as good checks like any of the super fast flyings, which, again, are all great in their own right and have distinguishable niches. there are also less common options that are still solid choices overall to revenge kill it like scarf mien, golisopod, scarf hera, bewear, etc. they might be scared off by the other sets, but in the grand scheme of things you're not making the most use of what makes zarude so good and are allocating roles to it that can be fulfilled by other mons.
beyond that, while i do firmly believe that it is the most splashable mon in the meta, there are also times where it's like...kind of hard to get it in, especially now that slowking is gone (which also was great for the tier, but whatever) to teleport it in. the loss of slowking and the influx of more breakers like volcanion, cobalion obviously, and maro-a being added to the tier, while not nullifying its effectiveness obviously, make it a bit more restricted in how it'll be able to come in.
in a lot of games in practice, both playing and watching, the most effective method of using zarude is what i've described above, making it so that the other sets, while not necessarily unviable, aren't worth the opportunity cost of not using boots with jungle healing + uturn, and as such the cases for its other sets compounding to it being theoretically unhealthy aren't really valid because you don't have to put in nearly as much effort in dealing with sets that are lacking all of the aspects of the aforementioned set. it basically is what is the most notable feature of how good it is as a glue.
I'm not super convinced on Zarude either - would much rather see a suspect later on if we have to go through the ban route - but to me that kind of hits on what the problem is with Zarude in a way. It's not the only mon that can do all these things, but because it's here it's considered to be the only one since it completely erases the competition from viability. Consider this, how does Zarude deal with Suicune or Zygarde better than, say, Celebi? It really doesn't, and in fact Celebi has some nifty tricks that would allow it to shine in those roles even better, buuuut using Celebi in a Zarude meta is completely handicapping yourself. You could use Roserade too, except that's using a grass that isn't Zarude and I have tried that, it comes with a ton of problems too. Obstagoon is a good mon too, but using another dark has some handicaps as well, and it's not like Zarude cannot break through setup either.
It might be early though, and like you said Slowking was a big reason why it was almost essential to any team. Cobalion does help (although I have seen way too many replays in preparing for ltpl of Zarude completely walling pivot Cobalion with that stupid double recovery set) but it's one mon. I do think though that if Zarude keeps that up and proves it's just as much a mainstay in its ability to pivot without consequences, force some of the same mons on every team and just completely shuts down usage of half a dozen mons because they are not Zarude, then it's certainly worth suspecting.
this seems less of a "this mon is broken" thing and more of a "this mon can lead to a stale meta" sort of thing, and that aspect isn't really applicable to the tier right now. responding to each of the mons you brought up in particular here, celebi isn't worse off just because of zarude, it's worse off because it's not that strong and struggles to really get itself going in any regard. the only sets that i think could be worth running in this meta are hw shenanigans for teams that you play balls out with (rain comes to mind but there are probably others), or something with pollen puff to dick zarude. it being bad isn't a direct result of zarude and honestly out of any of the non zarude grasses i can think of it'd probably be the worst, even tangela and virizion seem like they have a good niche right now. roserade is a great mon too, because it has access to spikes and sleep powder, both of which are pretty important means of progress overall. it's worse off in some aspects than zarude but not enough to the point where i'd rule it out entirely as an unviable choice. obstagoon is actually really solid too, and it goes beyond the scope of being another dark. having that immediate power that lets it blast through fairies more reliably than zarude can ever hope for,
and having knock off in a metagame where most teams have like, 2 boots users minimum if we're being really generous because of how essential hazard immunity is, is a massive boon to any team. there are a good number of other examples i could list but you get the idea.
zarude is splashable, yeah, and does centralize the meta. but that doesn't mean it's inherently bad for the tier. like, this isn't even new for the tier conceptually either. looking back at past metagames this year, there were points where things i found that mons like charizard and jellicent were legitimately hard to justify not using because of the same thing what zarude is theoretically doing, in providing significant roles for a team with not that much opportunity cost, and it was way worse back then because we just did not have that many options. but they weren't really broken, they just did so much that it was way easier to just slap them on a team than rack your brain over how to cover things without using them. what makes it so that zarude, something that is still amazing but didn't come close to them in this regard, making this tier stale when we have a lot of options to choose from? in circuit playoffs, despite a lot of teams having zarude and slowking, there were a lot of significant ways you could go about building that make (or made i guess) them great additions to the tier because of how much they contribute.
Several people so far have made vague allusions to Zarude counterplay. What are some concrete, easy-to-fit examples? Are there ways to maneuver around Zarude in a battle that aren't obvious on paper?
A popular opinion is that Zarude holds the tier together, and removing it would open a Pandora's box of overbearing threats. This reminds me of the situation that late-gen SM UU faced: Scizor and friends kept each other somewhat reasonable, but a significant number of players disliked their presence, and banning any one of them would require action on a lot of others and completely change the metagame. It's early days yet, but is this a scenario we want to risk ending up in by preserving Zarude? Preemptive apologies to any SM UU players if I'm misrepresenting the tier here, feel free to correct me.
I've yet to start playing SS RU for myself, but I've been paying a good amount of attention and would love to see more thorough discussion on this important tiering moment.
already went over the counterplay aspects in the first part of this post so not gonna go into that again. most of the people ive talked to have felt that zarude is a positive presence, but there are a lot of key differences between the impact zarude has and what scizor had in uu. putting it bluntly, the pacing and how you would play sm metagames and ss metagames are completely different, and this isn't even just a sm uu vs ss ru comparison. back then, you didn't have boots, and you did have z moves and the existence of pursuit. for scizor, it worked in a way that there were no hard counters because every set you could run on it was incredibly good in its own right, going beyond even just being splashable since z moves can blast through literally anything and pursuit was great in wearing down its checks (scizor ran pursuit on its own but common partners also had it so the typical answers you'd have for it were always at risk), and said answers didn't appreciate being chipped by hazards either. you have to dedicate way more resources on a team to covering yourself against scizor than you would against zarude in this tier. i can't really say for certain what a scizor ban would have done to uu, but i think in comparsion it warped the tier way more than zarude ever could here.
for what its worth i'm pretty sure zarude's not getting banned from talking to most ppl so this post is probably useless, just wanted to give my thoughts.