Hm i disagree with you Disarray, I think you would learn a lot of things in battle that can't really be taught in training, and i think theres plenty of examples throughout history where the more experienced troops perform better than raw recruits :p
Also for the morale, true that the part about how willing a soldier is to kill others is debatable but I think his own fear of dying and thus unwillingness to enter battle has to be diminished with each battle, like how pretty much all things are scarier the first time you try it, parajumping for example.
Peace
