The general idea is that you should create an empty forest root domain with
no users or computers (other than DC's). So your root domain of company.com
would be empty and you would then create your 'production' domains
child1.company.com, child2.company.com etc. that hold all the accounts. It's
a good idea in theory but is a non-starter for anyone other than large
companies due to the extra hardware costs involved (at least two extra
servers both doing hee haw). Among other things, this tactic supposedly
provides security for your Enterprise Admin accounts by keeping them
isolated.
