What different roles PCL-181 (newer) vs PLZ-05, both are 155mm ?
Both have same gun i.e. PLL-01 155mm gun. Y20 tranport jet can carry two 25 tons PCL-181 while it can carry only one 45 tons PZ-05, quick air lift in larger number onto islands is a plus point for PCL-181.
Tracked and wheeled vehicles have their pro and con on mobility on different ground surfaces on high plateau, desert, humid jungle, soft muddy ground, plains, bridges etc.
Development of PCL-181 was to complement PLZ-05. PCL-181 is more likely to be used for quick expeditionary deployment in sudden flare up areas like Yunan-Myanmar borders, Xinjiang and Tibet.