Xiangcheng is located in the south of Zhoukou City, Henan Province, and belongs to the upper reaches of Huaihe River. Xiangcheng was indeed in the northwest of Shouyang in the Eastern Jin Dynasty, and the distance between them was about 200 kilometers (a typical Yellow River flood area, deeply affected by war and natural disasters).
Shouyang in Bianhuang does have this place, which has nothing to do with Shouyang in Shanxi today. If there are similarities, it is purely coincidental. Shouyang in the Eastern Jin Dynasty was on the Fei River, probably located in Shouxian County, Anhui Province. You can Baidu about the battle of Feishui. This war is real, and the process is similar to that in the novel (Huang Yi just added some ingredients to historical events), and the outbreak place is really near Shouyang.
Ancient place names are not necessarily the same as today's. For example, the capital health care in the Eastern Jin Dynasty refers to Nanjing today, and later Jianye, Yingtianfu and Jinling all refer to Nanjing.
Now it seems that Henan and Anhui are located in the Central Plains, which is quite stable. However, when the North and the South scuffle and regime change, these places may indeed become "three caring areas". This situation is similar to that in the last century 10-20' s, when the big warlords were fighting, the Yellow River flooded and the people were in dire straits. Henan is controlled by petty warlords and bandits. It is normal for a group of people to control one or two cities, and some counties have even established their own political power (Zhenping and Neixiang).
So BianHuang set really had such a place, it's hard to say who, but in addition to historical figures, other figures such as Yan Fei, Gao Yan, Zhuo Shengsheng and so on are all made up by Huang Yi.
However, Emperor Wu of Song Wudi was indeed the founder of Liu and Song Dynasties in the Southern Dynasties, while Tuoba Gui, the Daowu Emperor of the Northern Wei Dynasty, was the founder of Xianbei regime in the Northern Wei Dynasty. Helian Bobo, who ruled the regime, was indeed extremely cruel and was indeed the invincible god of war at that time. Among them, Sun En Uprising, Huan Xuan's invasion of Jiankang and Tuoba GUI's massacre of tens of thousands of Yan soldiers in the north of Shenhe River are all real.
The biggest difference between a novel and history is fictional plots and characters, and then unrelated characters are put together to fight side by side or fight with each other, and decades of wars and events are condensed in three to five years. At least the rise of Emperor Wu of Song and Tuoba GUI was the result of half a lifetime's efforts, not the sudden rise of books. But he has been fighting for hegemony all his life, and only when he is 70 years old, he confronts Gui. Mu Rongchui seems to sweep the world in a year or so, which makes me speechless.
In the battle of Bianhuang, Mu Rongchui had no time to deal with Murong Yong of Xiyan, so he sent Murong Bao to lead the troops against Tuoba GUI. In fact, Mu Rongchui didn't start to crusade against Tuoba GUI until Xiyan was destroyed. The reason why he sent Murong Bao was because he was too old to fight. Tuoba GUI cut off Mr. Murong's post-war news. Murong Bao was worried that old Mu Rongchui would die when he went to war, and was seized by other brothers far beyond the Great Wall. He was eager to return, so he was given a chance by Tuoba GUI. Later, Tuoba GUI slaughtered more than 40,000 Yan soldiers in the north of Shenhe River, and the furious Mu Rongchui went into battle in armour at the age of 70. When the god of war was in power, Tuoba GUI fled when he heard the news. Mu Rongchui marched to Shenbei and saw the bones everywhere. The old man's remorse, sadness and anger could not be controlled, and he died of a serious illness. Since then, the Murong regime has vanished.