AnimController vs matching anim by track name

Hey guys, please, can anyone help me to solve the following problem?
* There is a character model (not Unity character, just generic) linked below a prefab. Note that the prefab is not made from the model itself, it is parent of the model.
* There is an AnimController (AC) on the model and another AC on the prefab.
* The AC on the model governs looping visual effect (artist needs a separate AC).
* The AC on the prefab is for usual animations (idle, attack...)

Now the problem. When I export animation, it expects the root bone (and, respectively, all other bones) to be direct child of the object I apply it to. BUT, there is model between prefabAC and root bone. When I link an animation to prefabAC, all anim tracks announce "missing" objects to apply to. How do I make them take into account that there is an additional link in the hierarchy?

I tried 2 workarounds. First, I can manually select each track in Animator and edit its name (from "boneName" to "modelName/boneName"). We all know, this is impossible to maintain once anim production starts.
Second, in every animation in Maya I add a bone named "modelName" as a parent of former Root bone. However, in case we change the name of the model, we would have to reexport all animations with a different root name. Hardly a sustainable solution. Please, help.

Thanks for any advice. Cheers.
Peter

 

Come on guys, has no one had the same problem? Out of wit here... pretty please?