The formula below must be mising something that I can't quite get. Goal: If the 2 cells combo of the row data on the current sheet are found on either of the other two sheets, then bring back the data from the request ID column from the match found on the other two sheets, or blank.
=IF(OR(COUNTIFS({Sheet1 - E#}, [E #]@row, {Sheet1 - A/R}, [Vendor A/R #]@row >0, COUNTIFS({sheet2 E#}, [E #]@row, {sheet2 A/R}, [A/R #]@row >0) {requestID}, "")))