Yes, the Business actor concept in Archimate do make sense in conjunction with the organization unit concept in Togaf. At least the Archimate concept covers the Togaf concept good enough to make it usable. The match is to be found in how Archimate uses “departments” and “business units” as examples.
|Business actor||Organization unit|
|A business actor is defined as an organizational entity capable of (actively) performing behavior.A business actor performs the behavior assigned to (one or more) business roles. Examples of business actors are humans, departments, and business units.||A self-contained unit of resources with line management responsibility, goals, objectives, and measures. Organizations may include external parties and business partner organizations.|
So what could a meta model implementation pattern look like based on a UML tool?
UML::Actor<-Togaf::Organization unit<-Archimate::Business actor