The new Centralized Identity Management tool is a great step forward so that a User Admin can assign users to workspaces. A number of companies I have spoken to have expressed that in a future iteration we enhance this to allow the User Admin to assign model level roles, like "Regional Supply Chain Planner", "Controller", "Sales Manager", etc.
Reference https://community.anaplan.com/t5/Releases/Introducing-Centralized-Identity-Management-CIM/ba-p/100071