I'm not sure I understand what you are trying to achieve. Do you want to have a sentral /home folder for your clients?
/etc/exports are used on your file server to make them browsable for your clients (Via NFS). The clients, on the other hand, make an entry in /etc/fstab to mount their /home folder to the /xhome folder on your file server. If your client fail mounting your NFS-resource, the won't be a home folder, and that could be a reason why your clients wind up in "/".