Military History of Formation

The reason no-one would deliberately adopt this form of warfare (unless they had no choice) is that it visits untold suffering on the population - indeed, that suffering is necessary, to arouse the survivors to battle.

In contrast, the benefit of fighting with a more formal army is that the battle can be kept far away from one’s own civilians (at least, in theory), and a distinction drawn between civilians and combatants - with the rights of the former (again, in theory) respected.

I thought most of the killing by the anti-American/South side in the Vietnam War was done in pitched battles by the PNVA, not in the jungles by the VC.