The Sum of individuals is not always equal to the Total. For example in pages report the Sum of visits is not equal to the Total visits since there might be few common visits. This feature is critical when you apply a filter on the report. This is taken care well in the the Reports&Analytics. Always totals are dispalyed after deduping where ever it is required.
Metric Total in Reports&Analytics:
Whereas, Analysis Workspace do not display the metric totals specific to the filter applied in the reports. Workspace always display only the Grand Total and there is no other easy way to calculate the metric totals for the filter. Totals are not Sum of individuals always.
Metric Total in Analysis Workspace: