As far as I remember, it was required to de-install the original (SUSE) version of xine, because it interfered with the packman version. Another option would be the installation of mplayer, which has all required libs and codecs built-in.
YaST doesn't require a particular installation order. Surely, package dependencies have to be considered, but if you add the packman server to the YaST installation sources, this should be done automatically. Usually, no manual interference (e.g. hard links) is required.
If you want to use Xine for DVD playback, the most tricky part is libdvdcss. But the instruction you find on the packman website are very detailed. A script does most of the work for you:
http://packman.links2linux.org/?action=122