Stunfisk-Galarian deserves an analysis for this set
stuntfisk (Stunfisk-Galar) @ Leftovers
Ability: Mimicry
EVs: 252 HP / 4 Atk / 252 SpD /
Careful Nature
- Stealth Rock
- Earthquake
- Yawn
- Protect
The easiest thing to compare this to to explain its viability is Bronzong. So in terms of stats, you're essentially equally as bulky as max SpD Bronzong while you're about 8% bulkier physically, so stats are no issue. In terms of typing, you do lose Levitate Ground immunity but you gain Electric immunity. Practically speaking, this is okay because one of the most common Earthquakes is from Haxorus which kills Bronzong anyways (Rhyperior is another one which you lose the ability to counter sadly).
In terms of match up, I acknowledge you become a much worse counter to Roserade, Rotom-Wash, and Celebi. However, you get much better match ups now vs Toxitricity and Polteageist.
In terms of utility, it looks like you're a bad SR user because you cannot touch many floating Defoggers. However, this set fits on balance where Pokemon like Roserade and Sylveon work to immediately deter the Defogger (Rotom-W and Noivern). Combined with Yawn and Protect, you can actually force these Defoggers out and maintain hazards.
You can also compare this to Steelix, where you become much more reliable in checking the special attackers Steelix beats (Toxtricity and Sylveon) at the cost of a great amount of physical defense and Toxic and good Steel STAB.