The AWA version is not to be confused with the version of Automation Engine.
Automic Workload Automation is a "package" that contains components and content.
One of the components it has is the Automation Engine.
Currently, the latest AWA version 11 (latest version 12 is available as well) is 11.2.4_2016-12-19, which includes Automation Engine 11.2.3 HF2.
If you want to download just the Automation Engine component (and not the RA agents, etc), you can click on Downloads > Advanced Mode:
Component = Automation Engine
Sub-Component = Automation Engine
Version = 11.2 (or choose specific - 11.2.3 HF2)
and download
Automation.Engine {version} {hotfix} Image
Note: Automation Engine 11.2.4 is not yet released as of this time. Tentative release date is March 2017.