Re-use characters?

Okay, I’ve run into a snag getting caught in the web of Blender’s data linking while trying to flesh out a scene with a couple of characters.

Here’s my setup: I’ve got one .blend file that has an armature and a mesh for a character, both part of a Group for easy importing. In a second .blend file I created the set, and Linked the Group from the first .blend file (File > Link, then in Outliner, show Groups, right-click, link into scene, then convert object into Proxy). Great, now I can animate that character.

But now, in the background of the scene, there needs to be more characters, identical to the first in appearance (they happen to be cows), so I want to reference the first .blend file again; how do I do that? Selecting the existing armature_proxy and mesh object and Duplicating, or Duplicating Linked creates two armatures, and the mesh objects don’t know which to follow and get radically deformed.

in blender-2.49 there was a “trick” to duplicte the reference file and use each of this duplicates to link in an individual group — background: blender uses the filename to identify the linked-in-objects and if this filename is the same, blender cannot identify different objects, thats why there is only one object possible to link in.
For example in linux, the duplicated source-files could be simple links to one base-file. So if you change the base-file all linked source-files will have the same changes, because they are the same base-file only with a different name. The different name makes it possible to link-in multiple independant objects, as much as you have duplicated source-files.