Group 1 - The article discusses the formation and leadership of the New Fourth Army during the Second Sino-Japanese War, highlighting its significance as a guerrilla force within the National Revolutionary Army [1] - The New Fourth Army was established in 1937, unifying guerrilla forces from eight southern provinces under the leadership of key figures such as Chen Yi and Su Yu [1][2] - The article details the four main detachments of the New Fourth Army, including their origins, commanders, and roles during the war [2][4][5][8] Group 2 - The First Detachment was primarily composed of Red Army troops from the Soviet area, with Chen Yi as its commander, who later became the overall commander of the New Fourth Army [2][4] - The Second Detachment was formed from guerrilla forces in Fujian and Zhejiang, led by Zhang Dingcheng, who played a significant role in coordinating military efforts during the war [4] - The Third Detachment, under Zhang Yunyi, was established from guerrilla forces in Eastern and Northern Fujian, contributing to the overall strategy of the New Fourth Army [5] - The Fourth Detachment was formed from the Red 28th Army and other guerrilla units, led by Gao Jingteng, whose leadership faced challenges during the war [8]