Looking at the tables for failing under fire or in melee, it becomes apparent that raw units will suffer worse than experienced or veteran units. They have a greater chance of failing tests in the first place. But they roll 1D6, experienced roll 2D6 and veterans roll 3D6. The results in the lower 6 of the tables are more severe. Raw units will run further from fire, and stand a 50/50 chance of surrendering if beaten in melee. Experienced troops have a 3 in 36 chance of surrendering, veterans a 1 in 216 chance.
Rather ingenious for such a simple set of rules.