Honestly speaking, it is already hard for a squadron consisting of hundreds of people to move forward as one is already a job hard enough for most people even if they are well trained. It would be even harder for some one to command a few hundred terrified soldiers with more than half being recruits to go backwards with out turning their heads engaging the enemies in front. One can try to walk back wards with his eyes covered and see how hard it is. In a regimental like this any one who makes a few wrong moves, like going back wards too fast and trips, can cause a devastating effect to the entire regiment, as the bigger sorrows are always caused by the smaller misdeeds before hand.