Test What a Different Model Adds to Review

A second model can give you another view of a migration or payment change. That is useful only if its findings survive inspection.

Different model families may fail differently, but they can also share assumptions, training material and blind spots. A different brand name does not establish independence or a smaller combined error rate.

Give each reviewer the same diff, requirements and relevant tests, without the other reviewer's findings. Ask for a reproducing case for each suspected defect. Compare valid findings, missed known defects and review cost.

Keep the second opinion where it adds evidence. Agreement between two models is still agreement between two models; it does not replace the test or the person accountable for accepting the change.