Hello, the image only shows several skin names and one character, without letting us guess what can be found in each skin. This makes judging if the skins are divided correctly hard.
Are the side/behind/front referring to the direction of the object? Normally, you should place in skins different outfits or cospetics for a character, not the different directions, because as you saw this multiplies the number of skins, and also presents several difficulties, like the fact that you can't animate or mix the different directions of a same object.
If you're not interested in mixing directions and you're new to Spine, you could separate skeletons (maybe just for the side, as the front and bach should be easy to reuse) as this way the skeletons are easier to control.
What I would do instead of having each direction in a skin, is to have each direction as a separate attachment/skin placeholder inside the same slot.
This means you would have a setup pose, likely from the front, and inside each slot you'd have 3 versions of the same object.
Then, in Animate mode, you can create the appropriate animations for each direction, where you turn the attachments/skin placeholders on so that the direction is correct.
For the side view this may be a bit more complicated given the bones need to be rearranged, which is why you can either separate it into a new skeleton, or try to follow the procedure in this stream: Spine: Twitch: video m 0wgqKquiQ
