After using Arctozolt and trying to make it work for a while using Sableye V, I found several complications that don't always appear on paper. For this particular stall archetype, a large amount of the problems I had with my deck seem to persist here. Arctozolt isn't so much a "stealth damage" pokemon as it is a "punishment pokemon", where it penalizes your opponent from playing a certain way. However, this is not exactly the greatest of strategies in practice, since your opponent can simply avoid that playstyle, and shut you down while acting less optimally themselves; the hinderance they receive is negated by the hinderance you yourself are receiving. If cards that attached energy from the deck or discard, such as Zacian V, Metal Saucer, Centiskorch VMAX, and the upcoming Melony card didn't exist, this deck would be better since any energy that entered the field on their side would proc the damage, but since they do, you are necessitating alternate routes of throwing on cheeky damage.
Personally, I've found that Spikemuth tends to be a larger hinderance than a boon to an Arctozolt player, regardless of what it's played with, since Boss' Orders means that an opponent who targets them down gets 20 free damage, meaning it only has an effective 110 HP, since the 20 it takes from Spikemuth will kill it. However, If you were to run SSH Toxicroak to add more oomph to your Koga's Traps, then it could create an interesting scenario with guaranteed damage on their turn from either poison or switching. Speaking of switching, YOU NEED MORE. 4 Switch or a combo of that plus Air Balloon is basically mandatory for any deck with bench sitters like Arctozolt, since you don't want to commit energy to something just to get it out of the active. You can accommodate the increase of switching cards in your deck with a lower count of Spikemuth since it punishes switching on your side as well. If you feel you need more than 2 stadiums, Wonderous Labyrinth Prism Star is also a valid option since it adds a need to attach more energy, meaning you force the opponent to take the penalty.
All in all, it may be better to just wait till June for this deck, which gets you Old Cemetery that adds 20 damage to all non-psychic type pokemon during Checkup phase (between turns) and Fog Crystal that acts as a Net Ball for psychic types, making your Cursola pulls much more consistent. However, if you want to play it before Chilling Reign comes out, I would suggest cutting sub-optimal cards like extra mimikyu (there's no point in stacking the ability with use only against Cheryl decks or decks with Mallow/Lana, and your Arctozolts are better Boss' targets anyway), Hop (there are so many better supporters we have, like an extra Marnie, Research, or Koga's Trap), Moomoo cheese (generally if you're healing, you want to heal for full, so it's not the greatest option here. Try the aforementioned Cheryl or Mallow/Lana if you're insistent on healing), Sigilyph (not enough punch for what it does, needs to be at least double if not matching damage dealt), or Great Ball (Just run Quick Ball) for a 2-2 line of Toxicroak to guarantee a bit more damage paired with the Stadium and energy. You could also throw in a Crobat, Dedenne, Kritcketune, or Talonflame V to use as your 1-of over Togekiss, who really isn't that great unless you have the VMAX for search, which seems to be missing here (Sigilyph could easily be Togekiss VMAX as well, if draw mons aren't your thing).
I personally love this archetype, but am willing to admit that it struggles to do well in the current format with the average threat having 300 HP and this style of deck requiring lower numbers to be competitive (unless you have a consistent way of using Sableye V, which has a great scaling attack with pre-damage from effects like poison, Arctozolt, etc.). Good luck trying to make this work, you will most likely need it on the jagged thorny path before you.
