The Hundred Regiment Offensive was a strategic mistake. The Japanese retaliation was highly effective and caused the Communist forces under Mao to shrink from 400,000 to 200,000 and never recovered during the war.
Mao's forces had no means to replace the weapons they lost because unlike the national army, they had extremely limited arms industry, lack of raw materials, nowhere to buy weapons and no one willing to supply them. Hence operations had to take into consideration how much weapons could be captured versus expended. Sometimes they would ambush the Japanese at night just to get them to fire their ammo so the guerrillas could pick up the brass later and reload them.
Large scale operations were not possible logistically.
Mao's forces had no means to replace the weapons they lost because unlike the national army, they had extremely limited arms industry, lack of raw materials, nowhere to buy weapons and no one willing to supply them. Hence operations had to take into consideration how much weapons could be captured versus expended. Sometimes they would ambush the Japanese at night just to get them to fire their ammo so the guerrillas could pick up the brass later and reload them.
Large scale operations were not possible logistically.