At least the first one (centos 7), resembles what NethServer does:
- build an RPM from Samba.org sources
- install additional packages
- configure system auth and services
In my first experiments I followed a similar procedure even on centos 6.
I obtained a working DC but I could not easily integrate it with other applications because kerberos libraries are not compatible. Also in NethServer port 53 (DNS) is already assigned to dnsmasq.
Also, NethServer prefers packages from upstream to quickly get security fixes: a recompiled samba package is not a great deal.