28 April 2021 Garand Picture of the Day

[ssgross]

many fights took place in just this sort of terrain

Yep. The Netflix documentary series "Medal of Honor" has one such account of fending off human waves charging up such terrain.

From my own experience, grenades "at the ready" would never be located outside or topside of the hole. They would be on our person or, if more were available than could be on person, piled in a box or somewhere protected in the hole within easy reach. The bags in the left of the pic are too close to be the "next position"? That's why I though OP, as it's all part of the same larger position. I could be wrong. My first instinct was these guys have all their firepower laid out and are taking inventory of what they have. I've never seen insignia at the rear, but I'm likely too young to have seen or noticed many enough period examples to say one way or the other.