git push sends more objects than it needs to

I just pulled from Linus' Linux repository ... and my
wrapper script alerted me to the fact that he had just
re-packed.

So, I logged into kernel.org and linked the new packfiles
across to my repo there, and did a "git prune-packed" to
clean away all the unneeded unpacked objects.

Back on my local box I merged all the new stuff that
had been pulled into my "release" and "test" branches.
(just a fast-forward for the release branch).

Next I used "scp" to copy Linus' new pack files to my
local objects/pack ... and ran git prune packed here.

Finally, after making sure that release and test
branches still built with all the new stuff I did
a "git push" to update my kernel repo.  I saw this:
updating 'refs/heads/test'
  from 0711c558ff3cf4d1e498a9686f4d8ce48aa8d79f
  to   2e488d3f8f299eb0ed826055bc30003e2c27d909
updating 'refs/heads/release'
  from 8a212ab6b8a4ccc6f3c3d1beba5f92655c576404
  to   581c1b14394aee60aff46ea67d05483261ed6527
Packing 10785 objects
Unpacking 10785 objects
 100% (10785/10785) done
refs/heads/test: 0711c558ff3cf4d1e498a9686f4d8ce48aa8d79f -> 2e488d3f8f299eb0ed826055bc30003e2c27d909
refs/heads/release: 8a212ab6b8a4ccc6f3c3d1beba5f92655c576404 -> 581c1b14394aee60aff46ea67d05483261ed6527

Now the "unpack" on kernel.org did the right thing and noticed
that over 9000 of the objects were already in the packfile.  But
I wonder if it couldn't have been smarter and not sent them?

Or am I just subverting the whole paradigm by hand-copying
packfiles around?

-Tony