This is a bit of a causal inversion. You know, Sun Shi's men have been working in Yuan Shu. From Sun Jian, they followed Yuan Shu to fight Dong Zhuoqi from Changsha County to Nanyang County. Sun Jian and Sun Jian's men have been fighting under Yuan Shu's authority. For example, Sun Ce's uncle Wu Jing has been working for Yuan Shu. Sun Jian was killed by Howie when he attacked Liu Biao for Yuan Shu. Sun Ce returned to Qua, Jiangdong for burial with Sun Jian's body. Since then, he has been attached to his uncle, Danyang satrap Wu Jing, not relying on Yuan Shu. At that time, Sun Ce once asked Yuan Shu to return Sun Jian's old staff, but Yuan Shu did not allow him to send Sun Ce to Sun Ce to take refuge in Wu Jing. Later, Sun Ce recruited a team of hundreds of people in Danyang, but this team was destroyed by the commander Zulang of Jingxian County. Sun Ce had no choice but to go to Yuan Shu again. So at this time, Sun Ce didn't act very tough. Only in desperation take refuge in Yuan Shu and attach to Yuan Shu. After that, Sun Ce became famous in Jiangdong World War I, and then he became famous in the world. At that time, he was Jiangdong bully.

Sun Ce was able to lead troops to Jiangdong, mainly because the existence of Jiangdong in Liu You at that time was a great threat to Yuan Shu. Yuan Shu's development in Huainan was the result of being defeated by Cao Cao and Yuan Shao. Yuan Shu was originally entrenched in Nanyang County, but suffered the blow of Cao Cao and Liu Biao's lack of food. In desperation, he fled to Jiujiang County of Huainan, and finally killed Chen Wen, the Yangzhou secretariat appointed by the court, occupying Huainan area of Yangzhou. But then the court sent Liu You as the Yangzhou secretariat. Because Yuan Shu occupied Huainan and Yangzhou to rule Shouchun City, Liu You had no choice but to cross the river to Qua in Jiangdong, and sent troops to defeat Wu Jing and Sun Ben. Yuan Shu sent Hui Qu with Wu Jing, and Sun Ben continued to attack, but the attack for a year had no effect. Liu You's presence in Jiangdong made Yuan Shu under attack. At that time, Yuan Shu was bent on developing in Xuzhou, so it needed a stable rear, and it was beneficial for Sun Ce and Liu You to fight each other. Sun Ce is like Yuan Shu asking for an attack on Liu You at the moment. According to historical records, Yuan Shu wanted to have Liu You in Jiangdong and Wang Lang in Huiji County. Yuan Shu assumed that Sun Ce would not have any great development, so he asked Sun Ce to lead troops to help Wu Jing attack Liu You.

You should know that before Sun Ce crossed the Yangtze River, Yuan Shu gave Sun Ce more than 1,111 soldiers and horses, which was obviously not enough to deal with Liu You. However, Sun Ce was strongly supported by Zhou Yu, Zhou Yu's uncle, Zhou Shang, who was the governor of Danyang at that time. Zhou Yu used Zhou Shang's influence to vigorously support Sun Ce, including rations, soldiers and ships, which made Sun Ce's power soar, and then Zhou Yu followed Sun Ce across the Yangtze River to attack Rong. This estimate even Yuan Shu didn't think of.

after crossing the river in Sun Ce, Yuan Shu began to storm Liu Bei. Liu Bei took in Lu Bu at that time, but he didn't expect Lu Bu to betray Liu Bei and take the opportunity to attack Xiapi City, which led to Liu Bei's crushing defeat. Since then, Yuan Shu has sent troops to attack Lu Bu, and the result was defeated by Lu Bu. It can be seen that Yuan Shu's center of gravity was not in Jiangdong but in Xuzhou at that time.

To sum up, Sun Ce was not famous before crossing the river. Secondly, Yuan Shu thought that Sun Ce would not do much after crossing the river, and wanted to send Sun Ce and Liu You to fight each other. Finally, Yuan Shu wanted to attack Xuzhou, so he agreed that Sun Ce would take more than 1,111 people to pacify Jiangdong, but he didn't expect Sun Ce to capture Jiangdong with Zhou Yu's help and outstanding ability.