I just went by your requirement.
Just read up the documentation about appendcols and join. Specifically, appendcols synopsis states that it "Appends the fields of the subsearch results to current results, first results to first result, second to second, etc." In your case, the subsearch returns just one event (the total stats count), and that is why it was getting appended to only one event from your main search. In case of join, all events are combined based on common field (if none specified)...
Hope this helps.
... View more