[Samba] idmap config / Is it necessary in my smb.conf file?

[lp101]

     I'm unclear on exactly if I need this in my smb.conf file. I've 
provisioned my domain with --use-rfc2307 but did not do any further 
mapping of UID and GUID in my smb.conf file. I'm currently running 6 
Samba4 DC's and am in the process of adding member servers for file 
sharing. Following the wiki for AD Member Server setup I'm asked to 
enter idmap config data in my smb.conf file. This is what spawned this 
question. Must I go back to my DC's and enter this info prior to setup 
of the member server and join? I'm currently reading this link for 
additional info. 
http://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/idmapper.html 
Thanks.

idmap config *:backend = tdb
    idmap config *:range = 70001-80000
    idmap config SAMDOM:backend = ad
    idmap config SAMDOM:schema_mode = rfc2307
    idmap config SAMDOM:range = 500-40000


-James