You definately can use ACE's CLI, or even the ACE's XML interface (with DTD) to configure the ACE.
ANM's goal is to provide a provisioning and operations GUI that aids operators in those tasks, especially for larger ACE implemenations. Even for smaller shops, having ANM-SERVER-xx-K9 available for $0 makes this available for even just a pair of ACE. Some shops will find CLI is all they need and want, others require a GUI totally, while others will have needs for both.
DK