unfortunally, this is limitation of JSF impl,
since JSF is the entity which reads all resource dependencies of components and renders resource links to the page,
but what I would suggest you is opening issue in JSF spec  (and impls),
you can link to Yahoo performance recommendations,
and I encourage you to create request for this feature in RichFaces ,
since we may find the workaround which could be implemented in scope of RF.
I personally would really like address such kind of issues!