[Perdition]

It matters significantly more if your youkai are underleveled than a player character is. Youkai have lower stats per level because they have to. If you could summon player character level mobs en masse it would be a total shitshow.

Honestly, at level 60 you'll find that pretty much any youkai will do decent damage until you get to higher level BDPs, but even players suffer there. There isn't a whole lot you can do about level 70+ snakemen mages and wings of fire if you're trying to use magic damage. Conversely, you'll find yourself in a similar situation without defense or armor shredding against jammers and other physically defensive mobs.

There are also youkai that do more damage than fairies. The fairies aren't exactly meant to be defensive power houses.