Why aren the DRAWORDER settings in attached xrefs honored?
This is a limitation noted in the R14 readme document. You might consider re-ordering the contents of the attached drawing by manually copying the object you want to appear on top so that it is at the end of the database, then remove the original object. Another suggestion mentioned in the readme involves uses the WBLOCK command to save out the contents of the xref file, and XATTACH to attach this new drawing in place of the original xref. See the readme file for more detailed information.