First of all, when Shi Dakai was in a desperate situation on the Dadu River, Luo, the governor of Sichuan in the Qing Dynasty, arranged for the local toast to persuade Shi Dakai to surrender. Shi Dakai did go to the toast site to negotiate. When the Sichuan toast refused to let him go, Shi Dakai made up his mind to trade his life for his subordinates, so he was arrested without much resistance (of course, Shi Dakai's subordinates were slaughtered afterwards). So it was true or not that the Qing court advised Shi Dakai to surrender at that time, at least on the surface. I think Luo should be trying to catch Shi Dakai, an important figure in the Taiping Heavenly Kingdom, so it is more likely to persuade him to surrender.
Let's take a look at the time when these people were arrested and demoted. Wei Jun surrendered to the Qing Dynasty in 1858. At that time, not only did Yang, commander-in-chief of the Qing navy who had contact with him, couldn't believe it. Even Zeng Guofan and Hu Linyi, who learned the news later, couldn't believe it (I have to say that the generals' revolutionary beliefs were very firm in the early days of the Taiping Heavenly Kingdom, and it was difficult for the Qing government to successfully surrender). It can be said that Wei Jun was the first senior general of the Taiping Heavenly Kingdom to surrender. At that time, although some people said that the patio incident contained the strategic offensive posture of the Taiping Heavenly Kingdom, Chen Yucheng and Li Xiucheng successfully saved the day and re-established the situation. It is difficult for the Qing Dynasty to win. Therefore, an influential general like Wei Jun could not be easily killed by the Qing Dynasty. He should be an example to attract other generals of the Taiping Heavenly Kingdom. At the same time, due to the relationship between Wei Jun and Wei Changhui (in fact, Wei Jun was rejected and persecuted within the Taiping Heavenly Kingdom, and even worried about his life), the possibility of false surrender or surrender is very low.
Look at the time when Chen Yucheng and Shi Dakai were arrested. Chen Yucheng was arrested at 1862. At that time, Chen Yucheng had lost his stronghold in Anqing, and most of his elite troops were lost. At that time, Chen Yucheng could only send and Lai to Henan, Shaanxi and Guangzhou for conscription. It can be said that Chen Yucheng was a toothless tiger at that time, which is why Chen Yucheng fell in love with Miao Qian90. Similarly, when Shi Dakai was captured in 1863, there were not many people and horses, and there was no stable base. He is far away in Sichuan. Therefore, the threat of Chen and Shi in the eyes of the Qing court has been greatly reduced. Furthermore, once Anqing was defeated, it can be said that the balance of war between the Qing Dynasty and the Taiping Heavenly Kingdom was greatly tilted, and the Qing court occupied the absolute initiative. After the fall of Anqing, the news of the surrender of the Taiping Heavenly Kingdom began to spread.
In addition, the status of stucky and Chen Yucheng in the Taiping Heavenly Kingdom is very special, which is unmatched by Wei Jun. The Qing court can spare Wei Jun's life and achieve the goal of political surrender. Chen should not let this stone go easily.
Finally, there are many helpless factors in Wei Jun's surrender. Even to some extent, there is no possibility of survival without Jiang Qing, and Jiang Qing may still have a chance to survive. Chen Heshi are both heroes, they are not born. They were forced to surrender after being captured. Because of their character, they can't surrender. So the Qing dynasty had to kill them.