Man, imagine if Psykos is actually stronger than Boros and Tatsumaki can't defeat her. What's gonna happen ? The rest of the S-class are too weak to make any difference, and there's still the other Cadres to take care of. This would mean Saitama would have to intervene early (he's not supposed to come out till AFTER AG smacks every hero) and then what ? The entire final battle sequence is changed and makes no sense, it's never happened, Murata only inflates feats but never changes the outcome of a fight/arc.
Though, AG being > Boros is something that's very possible regardless.