Is it possible for Active Roles integration without having to install the full Authentication Service package.
No, not at the time of this writing, March 4, 2019.
Enhancement Request #798356 has been raised to investigate this and is being evaluated by project management.
Currently you must install the following software on the computer where you will install the Integration Pack:
ActiveRoles Server 7.0 or higher, including the Administration Service, Web interface, and ActiveRoles Server console.
Authentication Services 4.1.0 or higher.
You must install the Integration Pack on a computer running the ActiveRoles Server Administration Service.
The Administration Service must be running to make all the necessary changes to ActiveRoles Server.