According to a series of books written by Masaaki SUGIYAMA and page 449 of "Chugokushi 3" (The History of China, Volume 3) (published by Yamakawa Shuppansha) says that a purpose for organizing most of the Southern Yangtze Army with soldiers from the former Southern Sung Dynasty was to get rid of them, and they would cause social anxiety if left alone (in fact, to support this idea, no ship in which Mongol commanders were on board sank, and tombs of the soldiers joined in the Southern Yangtze Army have not been found in the former territory of the Southern Sung Dynasty).
江南軍のほとんどが嘗ての南宋の兵であり、放っておけば社会不安の要因となる彼らを厄介払いする目的もあったと言われる杉山正明の一連の著作、『中国史3』P449など（山川出版社）（それを裏付けるように、モンゴルの司令官たちが乗った船は一隻も沈んでおらず、江南軍に従軍した兵士達の墓も旧南宋の領内では確認されていない）。