What's up with Max Level Monsters in Lower Level Areas?

[Lisotte]

Seriously... Did my mission 1-x and ran into a level 83 monster in Horototto Ruins and am finding they added these monsters to areas all over.... WHY? How am I supposed to get my quests done when I can't find max level characters to help?

Is there any need to do the missions early level though? You do that and you find you can't do many because you reach one too high level. At level 99 though you can knock them all out at once.