User blog comment:CNBA3/Chapter 413 Review/@comment-1359322-20141222122607/@comment-9595671-20141223060622

Any other explanation would require us to go off screen to a degree. Like saying that there's more than 7 slayers and each had their dragons come out and attack the other Faces.

If there had been a Lighting and Poison dragon that showed up during the Face purging then I'd have believed something like that, but there wasn't so the more likely fact is that we translated wrong and the actual number is smaller.

Although when Wendy saw the other Faces they were all close together. Maybe there were 3000 but so many were close together that they were able to destroy hundreds or dozens at once. You can't really tell unless you get an official translation from the published manga book itself.