It's not posturing, because I have nothing to gain from any of this.
You wrote,
To me, it is the simplest thing in the world: soldiers and officers in the same regiments had to know each other. If they did not, to whom would the officers give orders? If not, from whom would the privates receive orders. This was not IBM, Sanskrit, the Normandy Invasion or the United Nations General Assembly. They did not do business with fax machines over a phone line with someone they couldn't see. These folks communicated through speech and hearing. They knew each other. They had to. Why is this so troubling to so many otherwise astute individuals? I truly do not understand why all the posturing is going on about it.
You are correct about most orders and commands in the field being transmitted by voice. However, orders given by a regimental or battalion commander are ordinarily transmitted to company commanders who repeat them. They aren't delievered directly to each enlisted man. In any case, there's no requirement that any superior officer must 'know' all his enlisted men. Enlisted men must recognize and respect superior officers, and any soldier who served under an officer for any length of time probably remembered him. However, you've explained that a field officer should haved known and after many years retained a specific memory of each enlisted men who ever served under his command. In addition to that, you've also asserted that a commanding officer like Hillary Herbert should have known specifics when a soldier was absent from his unit. Furthermore, he should be able to recall all of this many years after the war.
Roger, if I've misunderstood any of this, I'll be glad to apologize and move on.
Perhaps your memory of past events and people is sharp and complete despite the passage of time. If so, you are truly blessed with unusual abilities.
Company rolls created by memory by surviving veterans ordinarily show that they cannot recall first names of all members, and have completely forgotten the names of a few. Outside of company rolls composed by veterans, I cannot recall an example in which any one member could recall many of the officers and men who served in other companies. In the two examples of Alabama regimental histories composed by regimental commanders, William C Oates of the 15th Alabama Regiment included wonderful stories about some of the enlisted men that he knew. However, Oates frequently noted that the record on many soldiers was incomplete, and he couldn't add anything further from memory. The record composed by Hillary Herbert is similar.
Let me suggest this. If you have a friend who teaches school, ask how much they remember about each student in a particular class from many years ago. Ask about tests scores, grades, class behavior, absences and other details. If your teacher friend can't remember specifics about a long ago class that included a couple of dozen students, how would Hillary Herbert be able to recall particulars about a regiment that may have included as many as 2,000 officers and men over a four-year period?