Having read this post I've changed my opinion.most of this post is invalidated by you admitting that scizor does indeed need to be pretty much at max to successfully check what it needs to, which was baloor's point, not that Scizor can't check these pokemon at all. It is true for pretty much every pokemon Scizor checks besides like chipped SD weavile and Kyurem.
Scizor isn't consistent enough defensively to find a place on anything that isn't like momentum heavy offenses most of the time, which are definitely a relevant part of the metagame but not to the point where Scizor should rise to A off of em. Scizor fats mostly died off ages ago because other steels tend to take its place much better post Kyurem panic, and its appearances on other teamstyles are prettty sparse and mostly come down to forced role compression or getting mercilessly 6-0'd by Kyurem otherwise. It is good on those, but that's really about it?252+ SpA Choice Specs Tapu Lele Psyshock vs. 248 HP / 8 Def Scizor in Psychic Terrain: 138-163 (40.2 - 47.5%) -- guaranteed 3HKO
if its physdef or mixed psychic does even more than this
+2 252 Atk Life Orb Kartana Knock Off (97.5 BP) vs. 248 HP / 152+ Def Scizor: 277-326 (80.7 - 95%) -- guaranteed 2HKO
+2 252+ Atk Life Orb Rillaboom Superpower vs. 248 HP / 152+ Def Scizor: 285-335 (83 - 97.6%) -- guaranteed 2HKO after Grassy Terrain recovery
252+ Atk Iron Fist Melmetal Double Iron Bash (2 hits) vs. 248 HP / 152+ Def Scizor: 108-128 (31.4 - 37.3%) -- approx. 90.7% chance to 3HKO
252+ Atk Melmetal Superpower vs. 248 HP / 152+ Def Scizor: 121-143 (35.2 - 41.6%) -- guaranteed 3HKO
= you lose to thunder wave melm off of two flinches or more likely, one flinch because Scizor staying at max without roosting constantly and generating 0 momentum is a pipe dream
252+ Atk Choice Band Iron Fist Melmetal Double Iron Bash (2 hits) vs. 248 HP / 152+ Def Scizor: 162-192 (47.2 - 55.9%) -- approx. 87.1% chance to 2HKO
CB cares even less
+2 252+ Atk Weavile Knock Off (97.5 BP) vs. 248 HP / 152+ Def Scizor: 258-304 (75.2 - 88.6%) -- guaranteed 2HKO
0 Atk Technician Scizor Bullet Punch vs. 0 HP / 0 Def Weavile: 230-272 (81.8 - 96.7%) -- guaranteed 2HKO
If you've taken too much chip for u turning out to be a viable option and weavile is healthy (which is not an uncommon occurrence) you can lose this too. It still knocks you to get overwhelmed by its teammates at worst so w/e.
I agree Scizor isn't A material basically
At first I didn't understand why you would include setup sweepers in your calcs despite Scizor being best suited to momentum heavy offense/voltturn, which is very hard to set up against in the first place. But I now understand that it's to show how Scizor is ONLY suited to that playstyle, and wouldn't fit on other less offensive teams.
I do still think Scizor is very good at the role I described in my original post, on momentum heavy teams. But you've made a very valid point that this alone isn't enough to justify A rank.
Furthermore having looked at the viability rankings again, and seeing the mons that are currently in A and A-, I think it's clear that Scizor is not as good as the mons that are currently in A rank, and it would better reflect Scizor's place in the metagame if it dropped to A-.
So ig I'm nomming Scizor down now.
A -> A-
Oh and while I'm still writing, I really don't think Volc should have moved down. Not really nomming it back to A bc idk if I can form a good enough argument for that, but I still disagree with it going down.