First of all, one needs to understand Skeleton
A Skeleton is a hierarchy that is used to define Bones (sometimes called joints) in a Skeletal Mesh. In some ways, these Bones mimic a real biological skeleton due to their position and control over how characters deform.
FBX files imported into Unreal Engine as Skeletal Mesh assets will contain the character’s model, and skeleton. The character’s skeleton will be imported as an additional asset called a Skeleton asset, which you can view and edit in the Skeleton Editor.
Sharing Skeletons
An important feature of Skeleton Assets is that a single Skeleton Asset can be used by multiple Skeletal Meshes, so long as the Skeletal Meshes use the same general rig hierarchy. This means that the names and hierarchical order of your Bones must be consistent in order for sharing to work correctly.
Skeletons in Unreal Engine | Unreal Engine 5.7 Documentation | Epic Developer Community