Welcome to VCOps Communities.
If you open vSphere UI (https://<vcops-ip>/), open the dashboard and select a DC there is a widget (called Environment) that will show you exactly the number of clusters, hosts, vms, etc below. Is this working for you or you must use custom dashboards?
If you need I can send you a screenshot tomorrow.
It sounds like you just want some basic configuration.
You can use the configuration widget for "some" types of data, but you may wish to instead create a supermetric to countN sumN up the total cluster/host/vm resources under it. Some of these totals even already exist in the summary/planning attributes for these resources and don't require supermetrics. Always try to use what you have OOTB before going so far as to implement supermetrics.. sometimes less is more and you want to keep thing as simple as possible for cleanliness and supportability.
If you go with the supermetric, I'd suggest starting with something simple like a generic scoreboard to display these types of stats on your environment.
Brilliant, thanks for that!