Why did the Qing army have to go through Shanhaiguan?

Huang taiji didn't attack Shanhaiguan from the beginning. He entered Shanhaiguan from Daankou. He bypassed Shanhaiguan and attacked Beijing. The purpose of Rao Dao was that Zhao Lvjiao, the company commander of Shanhaiguan at that time, was loyal to the Ming Dynasty and unwilling to collaborate with the enemy. However, Shanhaiguan, known as the "first pass in the world", was easy to defend but difficult to attack, so he had to make a detour. As for Yuan Chonghuan, he is not a company commander in Liaodong (the company commander is a military attache and Yuan is a civil servant). Yuan's official position is "Ministry of War Shangshu and Deputy Imperial Advisers of Duchayuan, Military Affairs of Ji, Liao, Denglai and Tianjin", referred to as "Ji Liao" for short, and Ji Town is all under the jurisdiction of Yuan Chonghuan. In fact, Huang Taiji's success in breaking through the natural barrier of Jimen and entering Beijing is all related to Yuan Chonghuan. Thistle Gate Natural Barrier is the last barrier in Beijing. The Ming and Qing armies were deadlocked here, but Huang Taiji could not cross it. At this time, Yuan Chonghuan arrived, and he mobilized the troops of Governor Liu Ce who came from the front to reinforce. Then two days later, tens of thousands of troops of Huang Taiji successfully crossed the natural barrier and went straight to Beijing. As for how Huang taiji's army passed, there was a saying at that time. Xu, a national hero, said at the memorial service: "He worshiped Huan Yang for the main battle, but took the main money and even killed Dong Jiang Mao as a sign. The first emperor didn't allow heirs, so he took slaves to ransom, still refraining from taking the ephod to the front of the thistle, and Chonghuan waited for Donphan first. It is the enemy who arrives late, and the wine is rewarded. The night is still early, and the enemy suddenly formed an alliance with Chongqing, riding at the foot of the thin city, with the Chonghuan division behind the temple. " Translated into modern Chinese, that is to say, "Yuan Chonghuan fought on the surface, made peace secretly, and even killed Mao in exchange for the trust of the Qing Dynasty. Later, Chongzhen was not allowed to make peace, and Yuan Chonghuan persuaded Manchu to enter the customs and forced the court to make peace, but agreed that the Qing army was not allowed to cross Jiyumen (he just wanted to scare the court, not recruit bandits). When the Qing army arrived, Yuan Chonghuan took out beef and wine to entertain them. But at night, the Qing army suddenly violated the agreement, crossed Jimen and pushed Beijing to the gate, but Yuan Chonghuan fell behind. " It seems that Yuan Chonghuan's problem is not as simple as dereliction of duty, but collaboration with the enemy. However, after Qianlong Daxing Literary Prison, he personally overthrew Yuan Chonghuan's conviction and burned all the Ming Dynasty history books that were unfavorable to Yuan Chonghuan. Fortunately, some Han Chinese ancestors risked their lives to save some Ming Dynasty history books, and some Han Chinese ancestors went into exile in Japan with history books, just like Mr. Zhu Shunshui (Mr. Zhu Shunshui also thought that Yuan Chonghuan was a traitor, and there were records of "traitors before and after Levin and Yuan Chonghuan" in the Collected Works of Zhu Shunshui), so today we are fortunate to learn about the late Ming Dynasty, which is different from that recorded in Manchu history books, and Yuan Chonghuan, which is different from that recorded in Manchu history books. Regarding the marching routes of both sides at that time, I have a picture here for reference: