I havent used the servicegen task, just had a look at it on the BEA site. Even though you cant add those xmls to the ear file through the servicegen task, you can still write a
ant task which does this for you. That ant task can take the ear file, generated by servicegen task, as an input, unzip it and add the xml file and then zip it back to ear. There are ant tasks which allow you to zip/unzip archives and add contents to the archives.