I'm sorry, but I didn't quite understand how you set up your skeleton. If it is effective to split your skeleton for each animation, does that mean that the skeleton has a lot of images so that it can face many directions, and you want to split the skeleton for each direction? If so, unfortunately there is no special way to achieve this. You can simply create a skeleton for each direction that has the required images and animations, and switch the skeleton GameObject to be displayed at the appropriate time at runtime.
If your skeleton has many outfits and it is the cause of your skeleton's texture to be too large, then repacking it with only the displayed image can help. Though I am assuming that is probably not the case since your question does not mention outfits.
Please let me know if my assumptions are wrong to begin with.