Lets not also forget that she's not exactly the only Primal capable of splitting themself into multiple copies (*cough* Ifrit *cough cough*), so I agree with Moose - they were just temporary clones created by Garuda's will, seeing that meddlesome adventurer and their ilk was proving far more stubbornly difficult to subdue than she first thought. So she goes full on zerg-rush. Of course, that just ends up badly for her.

So yeah, I believe they're just budded copies of her essence that are not actually separate beings in the true sense (hence why they fall pretty quickly). They're meant to be a distraction to help give Garuda the edge.