The need for the system was promptly demonstrated when Supreme Commander Kaiser Wilhelm II proposed to concentrate against Russia, not France. Chief of the General Staff Helmuth von Moltke the Younger and Generalquartiermeister, Hermann von Stein convinced him that this was unthinkable because the thousands of orders could be quickly rewritten and because the French with their quicker mobilization and excellent railways would be attacking a German border in force long before the Russians. One of the eight German Armies was commanded by Crown Prince Wilhelm of Prussia, paired with Konstantin Schmidt von Knobelsdorf, a senior general staff officer the kaiser instructed his thirty-two-year-old son: "whatever he advises you must do". The system also removed uncertainty about the competence of Army Commanders Rupprecht, Crown Prince of Bavaria and Albrecht, Duke of Württemberg, though both were well-trained soldiers. Other armies were commanded by highly experienced staff officers, for example Paul von Hindenburg was given command of the Eighth Army, the only one facing the Russians invading East Prussia, with Erich Ludendorff as chief of staff.