G5s suffering from frequent HW failure

We’ve calculated that TWENTY PERCENT of all G5s owned by our customers have suffered from major hardware failures (Power Supply, Logic Board, Processors, etc.) of some sort. Two of the G5s were outright replaced by Apple after the internals were gutted TWICE. In my 10+ years of doing Apple hardware repair I have NEVER seen Apple outright replace a unit whole! Now they’ve done it twice in the same month! The failures don’t seem to restricted to any one particular model of G5 or one symptom and the units are spread across the city at different customers. Has anyone else been seeing a similar pattern of failures with their G5s?