| stats count will give you the count of events returned by the search of all the ep_winevt_ms* indexes.
Why do you think this is not the case?
ep_winevt_ms* - This index is mapped in Data Model Macros.
I want to exclude all other indexes in (ep_winevt_ms*) and take the count as 1 to know the unique indexes.
| stats count by index
| stats count