Among the founding generals, the chairman has always been very important to Su Yu, and before launching a large-scale campaign, the chairman will say: "Send a telegram to ask for Su Yu's opinion." However, before the Great War, the chairman did not support Su Yu's opinion, but supported another general. This general is not an ordinary person, but the founding general Zhang Yunyi, and this battle is the Battle of Lunan. 
The incident happened in December 1946, when Zhang Yunyi was the deputy commander of the Shandong Military Region, and Su Yu was the commander of the Central China Field Army and the deputy commander of the Central China Military Region. However, in terms of specific tactics, the two had a big disagreement, Zhang Yunyi hoped that the main force would attack Lunan, while Su Yu hoped to transfer the main force to the vicinity of Lianghuai, and the two sides would not make concessions to each other. This incident gave Mr. Chen a headache and it was difficult to make a decision. Although Zhang Yunyi is his subordinate, his revolutionary qualifications are older than his own, and he has very rich experience in war, and Mr. Chen does not dare to deny it easily. 
On the other side, Su Yu is also a winning general, and even the chairman admires him very much, so Mr. Chen does not dare to easily deny Su Yu's idea. Just when Mr. Chen was in trouble, Chen Shiyu, chief of staff of the Shandong Military Region, could not stand it anymore and went to Tang Liang, director of the Political Department of the Shandong Field Army, and jointly sent a telegram to the chairman, detailing the differences in the campaign and asking the chairman to make a decision. After seeing the telegram, the chairman replied: "To fight a battle of annihilation that is greater than the Subei Campaign, the Lunan Campaign is related to the overall situation, and the victory of this battle will be carried out, even if all the cities in northern Jiangsu are lost, there is a way to recover." Although the chairman did not clearly say who he supported, I believe everyone can see that this time the chairman is on Zhang Yunyi's side. It is said that after Su Yu saw this telegram, he did not speak for a day, and he was very unhappy. 
However, since the chairman made a decision, Su Yu also had the responsibility to lead the troops to start the Lunan Campaign with Zhang Yunyi, and finally annihilated more than 53,000 enemy troops, and also captured the two division commanders of the Kuomintang, namely Ma Liwu and Zhou Yuying. Of course, Su Yu is not a stingy person, and his dispute with Zhang Yunyi is only due to different views on the battle, and he still has great respect for Zhang Yunyi, a revolutionary veteran, in private. And Zhang Yunyi is also a well-respected and famous general in our army, and the chairman once praised him as "old and dignified, and his prestige is quite high." When the title was conferred in 1955, Zhang Yunyi, like Su Yu, was a general, but with the approval of the chairman, Zhang Yunyi could enjoy the treatment of a marshal, and he was also the only one among the ten founding generals, and even Su Yu did not have such treatment.