This approach is very like approach 2, except that selected assistants can be made more complex and have multiple tabs of information associated with them:
Here the "Product Assistant" has been made more complex and it has the tabs "History", "Bookings", "Availability" and "Basic Details" associated with it.
In using approach 3 it is important to remember that something like a "Product Assistant" primary role is to help users locate and display commonly requested product information only. It can be set up to be invoked from anywhere that product information is displayed anywhere else in your application.
You can get carried away with an Assistant and attempt to make it too powerful and too encompassing, to the detriment of the real "Product" business object in your application.