Hi, we have VMWARE monitoring through vCenter and we used “Read Only” default role, it is not discovering individual host CPU/MEMORY/NETWORK details, it is expected? for such monitoring we need to monitor each host separately?
Note: by individual hosts I mean the ESXI hosts which actually host the VMs
No, this works with vCenter without problem. Please have a look at the names reported back from the vCenter. In most cases the ESXi hosts had other names than expected. This ranges from IPs over FQDN names to some other strange names 
Now you have two options. 1 make a piggyback renaming rule od 2 create the host objects with exactly the same name as reported by the vCenter.
thank you @andreas-doehler , by the way I came across this guide which sets up separate individual hosts monitoring. I tried creating the host objects with matching esxi host names and it worked fine and I even see “Hardware Sensors“ (so esxhi host monitored by piggyback data from vcenter host monitoring) considering this is there any advantage of creating invidual esxi hosts monitoring? like creating users and rule on checkmk?