This is what I tried and I have LibreOffice 4.1.3.2 on Debian.  See
attachments for what I mean down below.

1. Export test.org to test.odt
2. Open test.odt, fix outline numbering and save as test.ott
3. Copy test.org to test-styled.org and apply test.ott as ODT_STYLES_FILE.
4. Export test-styled.org to test-styled.odt
5. I see that test-styled.odt has the required outline numbering.

   Don't be fooled by the numbering in TOC.  The TOC is not in sync with
   what the style says.  Just update the TOC (i.e., Update All) and
   everything will be just fine.

I am assuming that what I show here - with some variations thereof - is
what the OP wants to achieve.