Why did Fengchuan County merge with Kaijian County?

Xindu basin, Kaijian basin and Liangcun-Lengkeng basin are interconnected and are the largest basins in Guangdong and Guangxi mountainous areas. Kaifang, Nanfeng Town and Chang 'an Town in Fengkai County, Xindu Town, Putou Town, Lingfeng Town and Renyi Town in Hezhou, Guangxi, and Liangcun, Gangping, Lengkeng, Dagang, Lanzhong and Ma Ning in Huaiji County used to belong to Fengyang County. Speak the same dialect and open a room. Xindu basin, Kaijian basin, Liangcun-Lengkeng basin, now retain mutual marriage and the same customs. But in the end, why divide counties? It may be easy to rule. For example, when Jianxian County was merged into Huaiji County, the population who spoke studio dialect accounted for more than half, and asked to move the county to the original Lianshui County (Liangcun-Lengkeng), which made Huaicheng people in Huaiji County very unhappy. In addition, Qiaotou, Shidong and Gu Yong were once independent counties, and their dialects and customs were different from those of Huaicheng people, so they tried to restore the counties. In the end, the people in Huaicheng crowded out the builders, just because the cooperation between Fengchuan people and Deqing people was not pleasant. The provincial capital merged Kaijian County and Fengchuan County to form Fengkai County, as if it had been agreed that a town should be taken as the county government in the middle of Fengkai County, but then I don't know what happened, and Fengkai County is located in Jiangkou Town, a mountain city on the edge of Xijiang River.