Payables 3-Way match

In our Oracle AP (R12), the default "Match Action" on Invoice Workbench is "Purchase Order", although in Purchasing Option and Supplier Receiving Control, the "Match Approval Level" is set to "3-WAY", our users never used "Receipt" for Match Action on invoice workbench. According to Oracle AP document, 3-WAY match refers to Invoice matching to both PO and Receipt. If "Match Action" is set to "Purchase Order", is this real 3-WAY match when "Match" button is clicked? To have real 3-WAY match, should we change Match Action to "Receipt" on invoice workbench when invoice is created?

Thanks