When deploying additional domain controllers in a forest using Server Manager, why should you create a server group using Server Manager for the remote servers you’ll be promoting to domain controllers?
Quick check answer
So that you can more easily promote them remotely as domain controllers and manage them.
The above tip was excerpted from Mitch Tulloch's book Training Guide: Installing and Configuring Windows Server 2012 from Microsoft Press.
Mitch is a ten-time recipient of the Microsoft Most Valuable Professional (MVP) award and a widely recognized expert on Windows Server and cloud computing technologies. For more information see http://www.mtit.com.