Because Duan helped Song Jiang a lot, Song Jiang thanked Duan and let him sit on the top spot. In fact, in principle, Duan wanted to steal a good horse for Liangshan, but he was robbed halfway. When he arrived in Liangshan, he reported that he had cheated the castellan of Liangshan, which was a disaster for Liangshan. But as the saying goes, the disadvantages outweigh the advantages. Although Duan's series of behaviors seem to be harming Liangshan's interests, they have helped Song Jiang a lot.

The first reason is that Duan triggered the conflict between Liangshan and Zengtou City, which provided a good excuse for Liangshan to attack Zengtou City. In fact, according to the development of Liangshan at that time, sooner or later, it was necessary to go to war with Zengtou City, but Liangshan did not have a good excuse at that time. As a horse dedicated to Liangshan, it was taken away by people in Zengtou City, which gave Liangshan a reasonable excuse to attack Zengtou City. On the surface, Liangshan's desire to take back the horse is actually a reflection of Liangshan's need for external expansion.

The second reason is that Chao Gai was shot to death by an arrow when attacking Zengtou City. This even means Duan helped Song Jiang eradicate his biggest political opponent. Although Duan didn't pit Classical to death and help Song Jiang to take the upper position, it is an indisputable fact that Classical attacked Zengtou City and was shot dead with an arrow. Originally, Song Jiang was still racking his brains for not having a chance to get rid of Classical. This ingenious pen directly solved the big problem for Song Jiang. Can Song Jiang not thank Duan? It is not too much for him to sit in the top spot.

The third reason is that Liangshan is also a useful place. After all, Duan is not a person who is useless and knows nothing. You know, the horse that Duan stole is the mount of the State of Jin, and the person who can steal the horse from the stable of the State of Jin is definitely not an idle person. And Duan is familiar with the northern environment, Liangshan can use Duan's relationship to buy a certain number of war horses in the north, which is also Duan's value.