I have been producing various animations for game projects, but I have not developed a reason to use multiple skeletons in any of my Spine project files. I've been pondering about possible scenarios when I could make use of skeletons from importing project files.
I love making dynamic actions and poses, so I hope to express this through my characters' animations. But I usually do not use more than 1 base body for a character per Spine project file, because I want to avoid managing a ton of layers. This has limited me with creating smooth frame transitions from 1 Skeleton to another Skeleton (of the same character). I was thinking I can start importing project files and eliminate some guesswork from working on project files (Skeletons) individually.
In regards to player vs. AI interactions, I've been having trouble deciding how I want to organize my Spine files when an interaction needs to be framed consistently between the player and the AI, particularly when either the player or AI has a grapple move (i.e. grabbing the arm). Aligning the characters is crucial to make the animations look correct per frame transition.
In both the scenarios above, however, there can be body parts that would need to be recycled, such as the head or torso. In Scenario #1, in one project I used 2 different set of bones for the body but maintained the head, therefore using the 2 body bases in one Spine project. In Scenario #2, when I need a specific and direct interaction of 2 characters, I simply drew the 2 characters together for one Spine project.
My artwork style generally demands a lot of layers per character and I've been consistently using Constraints, which are not transferable between Skeletons. So, I may want to look for more management advice in the long term.