Using multiple 2D bone rigged sprites for one blend tree

I have two bone-rigged 2D sprites. One is front view and the other is side-view.

I'd like to use a blend tree to merge the states: front idle, front moving, side idle (right/left), side moving (right/left). However, since I've rigged the sprites separately, Unity seems to be treating them as separate entities. I created the front idle and side moving animations for now.

I've tried to group both sprites under an empty GameObject parent, and use an AnimationController on the parent. I am able to toggle the visibility of each sprite using keyframes on the "isActive" property. However, I cannot get the sprite animations to play when I use the Animation panel on the parent. Is there a way to swap between sprite objects in the blend tree? And a broader question: is it possible to play child pre-set animations in the animation of the parent? I've seen examples where the child is animated in the animation panel of the parent by adding properties (and keyframing each property in the parent animation). Ideally, I want to use anim files I previously created for the child.