It's a far bigger problem that the AI are usually glacially slow to aim and open fire. They have an hour-long turn radius and no aiming deadzone. On the flipside of the problem, it shouldn't be too hard to make them aim for longer at the appropriate ranges. If their guns are zeroed at 300m, they don't need to adjust it all for a normal firefight. The AKM is something of an exception to this in real life, because of the round trajectory.