Animation Collection in relation to Sprite Collections/Atlases

[Kirb]

Quick question; I couldn't find it anywhere else.

I have a large amount of Sprite Collections for enemy animations; and I separate all of the enemies by area into separate collections.

However; I've been using a single Animation Library for all enemy animations. My question is this:

Are all the atlases of the animations in the Animation Library being loaded, which would defeat the point of me separating the animations in the first place? Should I be separating all of the sprite animations as well? Or are only the atlases that are actually being used by the animation I'm using, being loaded?