At the 1795 engagement at Mainz, Schaal commanded two columns, one from the Army of the Rhine and the other from the Army of Moselle, that had been separated from their respective armies to take Mainz. However, when it came to the renewal of siege at Mainz, he commanded the united columns, one from each army, that comprised the "Armée devant Mayence" (the Army before Mainz). When the critical time came, however, Schaal was a mere figurehead implementing a strategy at Mainz that he had neither thought of, or approved. He entered retirement.