If you are looking for ways to monitor the productivity in Wrike, you basically have to go through the Stream view. That is not the most effective possibility.
Alternatively, you can create a report using 'modified' date. However, the 'Modifier' cannot be used as a selection, nor as a grouping option. The Creator or the Assignee are, however.
So, adding the field 'Modifier' as a selection and/or grouping option, would be very useful.