Is Anyone Warfare Guy
How is the legal international rule of war on soldiers carrying their wounded comrade retreating back to their territory line, would they be a legitimate target to be attacked and killed or such attack is fall under war crime?
IANAL - and I think you need a very specialized lawyer to really answer this. But bear in mind that ~~90% of infantry casualties in sustained ground combat are caused by fires from artillery, mortars, and such. Which are often "random", targeting a general area (especially roads and other lines of movement), and/or targeted by observers who really can't tell "carrying a wounded comrade to safety" from "carrying broken equipment to a repair/supply facility".