Second photo with the troops firing from a supported position does look like it makes sense for that style of stock.
Firing from the hip makes sense when clearing trenches or when you're actively "on point" in an infantry unit moving together. You're not going to take the time to aim, you're just spraying and hoping that the rest of the squad can take the time to aim at whoever you've managed to scatter.
Second photo with the troops firing from a supported position does look like it makes sense for that style of stock.
Firing from the hip makes sense when clearing trenches or when you're actively "on point" in an infantry unit moving together. You're not going to take the time to aim, you're just spraying and hoping that the rest of the squad can take the time to aim at whoever you've managed to scatter.