[quote=ShadowVentus]
Well, on both fronts, Erza had difficulty. The main difference between those two fights was the quantity of enemies. I can't quite remember whether she fought against 100 or 1,000 enemies in the Pandemonium event...
[/quote]

It was 100, with several supposedly supposed to be on even power levels with her, and even being on par with the Wizard Saints.