 Complete the following phrase:  His business qualities and common sense were greatly valued, though the temperamental differences between Müffling and Gneisenau often led to friction, especially as the former was in a measure the representative of the antiquated topographical school of strategists, to whom rightly in the main the disaster of the Battle of Jena was attributed. In the interval between the first occupation of Paris and the Hundred Days, Müffling served as chief of the staff to the Russian General Michael Andreas Barclay de Tolly and to General Friedrich Graf Kleist von Nollendorf. He was Prussian commissioner at the Duke of Wellingtons headquarters in the 