I have been reviewing the article.
UNIX and Windows Accounts in Zimbra LDAP and Zimbra Admin UI - Zimbra :: Wiki

One issue sticks in my mind is can I replicate the Zimbra LDAP (possibly OpenLDAP master-slave) which would include the Samba LDAP (following the article above)? I am not interested in multi-server Zimbra. Just Single-Sign on for Zimbra and Samba and just a fairly straightforward way have multiple LDAP copies for Samba.

Thoughts, ideas, etc...