Trying to hold several able-bodied military men from the enemy side while actively engaged in a war can't be easy. Shooting them in the leg to disable them is a practical way of lowering the risk of them being able to over-power you at some point. Whether the strategy is morally justifiable or not is a matter of personal values and context. I am pointing out that it is a war crime because it is, but I am not passing any judgement on whether I consider it to be justified or not. I don't know the context and I have not experienced what these people are experiencing. War is awful and I am sure that 'not breaking the law' is not one of the top priorities for people trying to save their and their family's lives and their country. I doubt that these people will be prosecuted for this crime.