Easy Armature Merge, a portion of a blender addon I am in the process of creating. It allows a user to merge the skeletal meshes of two seperate armatures in the simplest way I can currently come up with.
It functions by having a series of .json dictionaries that contains a list of possible bone names attached to a key that the script searches through to match up and standardize any bone names, ignoring case and extra digits (Such as .001), this allows other functions to be run on the script such changing the vertex groups, origins and parents of the skinned meshes easilly in a convention agnostic way that works regardless of how the bones are named, so long as they follow some type of convention (The dictionaries can easilly be added to from the "Save bone name to dict" button and having the bone who's name you want to add to the dictionary selected).
The key of the dictionary is the standardized bone name we want. --(I am currently working on allowing a user to choose a specific .json dictionary to prioritise the naming convention of, only using other dictionaries if there are bones that are not found. This is to avoid having too many options appear for different naming conventions as I want to expand the system to have a dict for each naming convention which is full of all bone names so it can be used with Unity, Unreal, Rigify and basically anything else desired..)
Armature Merge Feature
Add Bone Name To .json Dictionary Feature