Hi Alex,
The main idea is to have a parent and all the child object underneath in the same order. The Parent object is the only object that needs to be selected. The Hierarchy must always be the same to fit the Animation Clip’s information.
If you start for an object with many joints, and given the last questions, joints like a spine only, have them all in the same hierarchy “structure”. If the longest has seven and all other five or six, extend the shorter one so you can exchange the clips inside the project. Joints that are not used can be excluded during the Bind Process.
I hope this question was related to the previous questions, otherwise, let me know. I’m happy to look into it.
Cheers