A while back, we ran Network Sonar Discovery against subnets it did help us fetching all the server in those subnets but the Volume Utilization was left unchecked similar to the picture you posted. We had to run NSD again on the subnets only for WMI(provided WMI credentials)and the discovery was able to recognize the volumes and they are checked for being monitored. Hope this helps
I've provided Powershell and REST example to mimic the list resources functionality in the below mentioned thread. Please have a look at it. Only constraint is that we cannot choose the resources that needs to be imported as we do that in the UI as it is not supported via SDK now.