I didn't make space to mention this in my own review--I concentrated on what I thought was irrational--but I too had a lot of problems with Grossman's grasp of practical battle applications.
I noticed that glaring problem about bayonets. Aside from his lack of acknowledgement for the long history of impaling weapons, Grossman fails to consider alternative explanations for why modern soldiers might not stab. He does not consider, for example, that humans swing or perform an overhand stab because that exerts the most effect from untrained muscles.
Swung blows deliver a lot of force because they use momentum built up over distance, and it is easy to throw body mass behind the swing, effectively turning yourself into a pendulum or a bolo. Swings also takes advantage of the range of motion of the human shoulder and elbow, geared towards sweeping rather than thrusting for leverage. So it takes a lot less energy and feels empowering.
Unlike a swing, stabbing has potentially much less distance in which to build force. It requires a hip, leg, foot, and shoulder connection that physically feels uncomfortable. It also feels weak, whereas humans percieve a swing as very strong due to aforementioned basic physics and body structure. Swinging also compensates for a lack of accuracy; while a stab can be side-stepped or parried, a swing feels like a net sweeping over an area. Finally, humans may percieve stabbing as a vulnerable posture because it leaves the torso or limb exposed to a counter-strike, whereas a swing appears to curve back to the body for a natural guard.
In practice, a good straight strike delivers much more force and speed than a swing. However, body posture and motion runs counter to a human's natural state (which is to tighten muscles, rise up on your heels, raise your shoulders, and to distribute energy and nutrients instead of focusing them on driving your strike). It can take literally years of regular training to master. Most soldiers are lucky if they get a few weeks of supervised training throughout their career. This combination of inadequete training, perception of weakness, and natural physiology means that stabbing may be easily forgotten or ignored in the heat of battle.
But did you, sir, also notice the problems with his Civil War examples? He keeps talking about how muskets were fast-firing and highly accurate, as if they were modern semi-automatic rifles. He claims that combat casualties were unusually low for the given length of the battle. He argues that we should expect a much high death count in battles involving mass formations--a discrepancy only explained by soldiers who deliberately miss their targets.
Obviously, this line of reasoning is baloney. To begin with, he overstates the capabilities of the weapons; it helps that Grossman neglects to actually detail the muskets, leaving readers to simply imagine that he must be right. Grossman fails to note that the smoke produced by black powder cartridges obscured the battlefield. He fails to inform readers that muskets have a "rainbow" trajectory, in which a barrel aimed at the chest may shoot bullets right over the heads of an approaching enemy. He fails to observe that rifles could malfunction due to mundane reasons, not due to sabotage. His text assumes that soldiers do not take cover, and he assumes that they have adequete training to hit targets. From what I understand, many Union commanders emphasized rate of fire over accuracy.
So many assumptions and omissions--yet to the uncritical eye, Grossman is revealing some expert truth.