In my smb.conf I have:
config file = /xconf/samba/smb.conf.%h
... to handle having various samba configs for different machines in a directory that is shared by all Samba hosts. Unfortunately, "samba" won't start because it expects to see "server role = active directory domain controller" in smb.conf. It would see that if it followed through and read smb.conf.<host>.
To my knowledge, my use of smb.conf.%h should work.