Why are you trying to add extra armatures? To give extra movement to the body, left arm and possibly the mouth of the character.
Are you really wanting to add extra bones to the existing armature? No, or at least I don't think so, need extra bones to move different parts/additional parts of the character, but the bone that was added in edit mode is not showing up in the vertex groups, not sure how the mechanics of how the bones are added and assigned?