This is a good question. While you can (as Michael said) use Workflow Manager from within ArcMap, depending on the workflow, there may actually be no GIS component for a lot of the workflow - checking policy/procedure, filling out PDF forms, notifying stakeholders, etc.
In this case, managing the workflow outside of ArcMap and then calling it when you need to do a spatial task makes sense.
To achieve this I believe Workflow Manager can open an MXD directly, and thus start ArcMap without needing TAM. If you have a working document this is a good place to start, or you could simply open a blank MXD and proceed from there. You could also use 'Execute Executable' to start arcmap.exe directly if you wanted to.
Workflow Manager Step Types (10.2)