Each AC can only be contained once as a task in a MAS taskset. The option to run workspaces with parameters is described in the Statistica help topic "Overview: Batch Processing Using Workflows and Statistica Enterprise Server". The idea is to run an AC or a workspace multiple times within a task set, but with different parameters.
If you want to create global MAS dashboards with Site - Product - Parameter hierarchy this feature is IMHO really needed. Otherwise you need countless copies of your Analysis configuration - which is an administrative nightmare.