Take a look at GrandTotal.png & see the highlighted #. In the screenshot, my Total Using is set to "COUNT." Count is one of those functions where calculating COUNT by looking at the grand total rows will not match the COUNT by looking at the grand total columns. Currently, VA chooses to do the COUNT for rows instead of columns. To address this discrepancy, lets add an option in Analysis > Totals called "Prefer Column over Row Grand Totals". When this option is enabled, we'll chose to do the calculation in Column instead of Row Grand Totals.

This option should be off by default to preserve existing behavior.