User blog comment:CNBA3/Tartarus' Army!/@comment-5303512-20131104030254/@comment-7418318-20131105224646

I agree. When Erza fought Minerva, she was already exhausted from battling an enraged Kagura and had one of her legs severely hurt when the building came down on her, so we really can't judge how well a top-fit Erza would have fought against Minerva in that battle, without 2nd Origin or Nakama powerup.