Alice can suppress her monster form and appear as a human remember?
Maybe WW did that to make sure that H.E.R.O doesn't know that she's a Monster.
Your concerns are valid, but the reason I thought of this theory is because Thematically it makes sense.
As for how exactly it will pan out, WW can make it happen in many ways.
If Bernhardt and Malik is missing, don't you think H.E.R.O would set aside their differences and even take help from AOS if necessary?
Also there's someone in HERO that AOS is "terrified of", so it's unlikely AOS can do any damage to HERO even if HERO thinks he's not trustworthy.
So we have Alice, AOS, and many other unknown options.
And Ella and Deus are always Wild Cards, so there's that.
And where is Ella Doll? Very suspicious.
No matter what S.I.N wants, or how shitty of a person Ella might be, she's still probably on Humanity's Side, at least on the long term.
Another angle to look from it is, maybe Bernhardt and Malik's fight doesn't end anytime soon, and they keep fighting for months.
In one of the Dead End in Monster World, where in that Brothel quest you get trapped, the Universe ends.
Maybe that's a result of this Bernhardt and Malik vs Wasting Mother fight after years.
So, many ways to go about it, exciting stuff, let's see how it pans out.
Everyone wants to save the world, they just disagree how to do it.
Be it MC's Group, Ella's Group, H.E.R.O, S.I.N, M.O.O.N (including Tanos), or the World Government, nobody wants the Monsters to take over.