Frontline Team:
Solid Drive: Can cut BR by 99% to ~600k with Clothes Break but still can't damage Spawn of Apocalypse.
Juggernaut Drive: The Unstoppable Spear easily OHKOs Spawn of Apocalypse and her regular attacks damage after Clothes Break.
Judgement Drive: Can't damage even Clothes Break'ed SoA unless using Drop Slash which can OHKO even without Clothes Break (78 million + 75% BR reduction).
Judgement Core: Definitely able to damage Spawn of Apocalypse.
Gate Team:
James: Can't damage Spawn of Apocalypse.
Samael: Maybe*
Michael: Can't damage Spawn of Apocalypse.
Gabriel: Technically** can damage Spawn of Apocalypse.
Lucky: Can only damage Spawn of Apocalypse with War Book: METEOR.
Aquila: Can't damage Spawn of Apocalypse.
*If Sam stacks enough effects like Downgrade, Curse, and potentially Disintegrate he might be able to debuff a SoA enough to get through it's BR. Depends upon how his various spells effect it and how things stack.
**Gabriel can theoretically max out her damage at 154,500 and ignore 25% of her target's Base Resilience. That isn't enough to bypass the SoA's BR but if she has a stacking 10% increase per enemy killed. So depending upon how that stacks she could hit the 45 million damage needed to bypass the SoA's BR after either 60 (154,500 x 1.1^60) or 2,903 (45,000,000 - 154,500 - 15,450 x 2903) kills. I'm pretty sure the stacking isn't exponential so she'd need to rack up around 3,000 kills, because that is her peak with maxed out MM, to even begin to scratch at the SoA.
So everyone on the Frontline Team can reliably kill SoAs, except Sega but she can help with Clothes Break, while no one on the Gate Team can reliably kill them. Given that this attack of Goddess Red throwing endless waves of SoAs through the Gate and the Gate Team's job is to try and reach the Gate this seems unwise. That makes the vote a pretty easy decision.
[X] Join The Assault (Keep control of Anastasia)