You can't say those Pokemon are set-up fodder then say it's because of Latias' stats at +1. Proof they aren't set-up fodder:
120+ Atk Choice Band Scizor U-turn vs. 12 HP / 0 Def Latias: 374-444 (123.02 - 146.05%) -- guaranteed OHKO
252 SpA Latias Hidden Power Fire vs. 248 HP / 140 SpD Scizor: 280-332 (81.63 - 96.79%) -- guaranteed 2HKO
252 SpA Latias Dragon Pulse vs. 252 HP / 226+ SpD Zapdos: 103-123 (26.82 - 32.03%) -- possible 4HKO
+1 252 SpA Latias Dragon Pulse vs. 252 HP / 226+ SpD Zapdos: 154-183 (40.1 - 47.65%) -- guaranteed 3HKO
0 SpA Zapdos Hidden Power Ice vs. 12 HP / 0 SpD Latias: 98-116 (32.23 - 38.15%) -- 0.95% chance to 3HKO
252+ SpA Expert Belt Rotom-W Signal Beam vs. 12 HP / 0 SpD Latias: 149-178 (49.01 - 58.55%) -- 61.33% chance to 2HKO
252+ SpA Expert Belt Rotom-W Signal Beam vs. +1 12 HP / 0 SpD Latias: 101-120 (33.22 - 39.47%) -- 15.23% chance to 3HKO
252 SpA Latias Dragon Pulse vs. 248 HP / 8 SpD Rotom-W: 123-145 (40.59 - 47.85%) -- guaranteed 3HKO
(I realized I did Dragon Pulse on all of these, Psychic isn't SE against any so the damage is actually exactly the same)
So really, you can't set-up on Scizor or Rotom-W. The only two mons you can set-up on are a CC locked Terrakion and Zapdos, but you have to set-up so much on Zapdos to the point where you could just send out something else like Garchomp to deal with Latias. Your calcs didn't show what you needed, where you need to set up at, so I just can't choose Latias. Sorry.
I really would like people to think about DDance Haxorus, especially with Yache Berry, as it looked to me that other than Banded Tyranitar, Landorus-T, SD Gliscor, and Banded Conkeldurr, it was the only thing capable of dealing with Zapdos and actually being able to threaten something else.