Linking group is an efficient way to manage your project. You can link a charactor ‘group’ to animate him in the set before making small changes on polygon, UV, or many things later. And the changes will be carried over every scenes the charactor is linked.
You might, like me, keen on saving every version of source file, just in case anything goes wrong, and end up with many different versions of the same charactor.
before final render, with the master scenes linked to different source files, you’ll need to re-link them so that every scene links to the final one.
so, switch the outliner to ‘datablock’ view and find the ‘Libraries’. You’ll see ‘lib’ of every files that’s been linked into this scene.
Expand the ‘lib’ to find out which one’s which by its ‘File Path’
You can change the file name to the correct one. After saving and reloading the scene, it will be re-linked.