Lotta people be so quick to powerscale. From one line text.
Big Mom is softening up Pageone and Ulti to make it a more even fight for Ussop and Nami. More importantly this gives Ussop and Nami a quick reprieve to go to the live floor
Luffy falling knocked out, again it's without any context. Luffy doesn't get knocked out for long, same with Big Mom he'll either wake up at the right moment or be saved y someone and go back up.