More randomized walking. When walking at a slow pace so go ai and player almost 90% in the same position. With one arm dangling and the other on the weapon. 10% is used to the second position with both hands on the weapon. This makes the soldiers look like robots when everyone almost always goes the same way. They could also change the animation time to time.
Moreover, when they go in anitmationen with both hands on the weapon, the same walk sounds like the other animation which makes the sound does not sync with the steps.