That works pretty normal. I believe the VMware credentials are used to query data from VMware servers only, not on the actual guest virtual servers as those should use WMI/SNMP to get more detail information. However, part of the information that can be polled from VMware servers are the list of associated guest virtual servers.
To gather more detail information about the guest servers, ensure the following items to be included in your Discovery and see if it helps:
- VMware server and guest servers’ IP addresses
- VMware credential used by the VMware server
- WMI or SNMP credential used by guest virtual servers