The main reason was that Southern Mountain was a mining area, and the largest iron mine in Great Nan was located there. Almost all the iron used for the weapons and armor of the Great Nan army came from Southern Mountain.
It could be said that this place was a military stronghold of Great Nan, but every winter there would be a long period of cold snap, and most of the miners here were from south of the river.
South of the river was mostly snow-free, so the people who came here would be so overwhelmed by the wind and snow that they could not lift their heads. Every year, people would freeze to death, and the government would prepare winter supplies for the mining area when autumn came.
Otherwise, by the time spring came, there would be a shortage of iron for repairing weapons and armor.
At that time, if an investigation was conducted, someone from the Southern Mountain authorities would always have to shoulder the blame for the delay in military affairs.
