There is nothing to improve - you’re missinterpreting the Domains - UCS has it’s own LDAP Domain where the 1st server gets the domain master. On every additional server you can select the role DC Backup Server this has nothing to do with SAMBA (MS AD) its only an UCS LDAP Domain Backup Server role.
In a SAMBA or MS AD Domain you never ever have a DC Backup role as there are all DC’s equal.
So if you install an additional UCS Server in the domain it does not make sense to auto install SAMBA on an DC Backup server as you don’t need samba when not using Active Directory services in the domain
rg
Christian