We may have only one source on a particular topic or event and we make judgements about its credibility and its perspective and place some degree of reliance on its historical accuracy. If we have two sources we do the same with each plus compare and contrast the two with the hope of greater understanding. We repeat the process with each additional source. Over time, we get a general sense of the context of the events which introduces a new perspective on how we perceive and judge each source.
When I had writing assignments in school, my teachers told me to write about something I knew about. I have a better appreciation now of what that meant. The book by Rampp and Rampp is a perfect example of authors writing about a topic they knew practically nothing about. It may have been interesting to them. They may have gathered much research material. But they didn't know about the topic and misunderstood and misrepresented the materials. In addition, they, like most authors, felt compelled to "spice it up" to excite the reader and keep their interest I suppose -- I have often joked that "creative" writing should be banned from public schools. We live in a world where everything is "hyped".
I often mention the much published error that Capt Greeno escorted Chief Ross north in mid-July 1862 when actually it was Col. Cloud in early August. I use this example because about 75% of published "history" make this mistake. This is one of those perpetuated errors you and others mentioned. There are sufficient primary sources, not the least of which is the ORs, to be reasonably certain of this but subsequent authors relied on secondary sources instead of searching the available primary sources.
What I despise the most is when an author embellishes the story for dramatic effect and thereby not only misrepresents the facts but distorts the whole context of the events. Several popular secondary sources mention, without details, the Union capture and destruction of Ft Davis. These sources make passing comments of Phillips' expedition "to attack the fort", "driving the Confederates out", "the booming artillery", and the like. As I said, these comments are made without any details because their are no primary sources that suggest the above occurred though there are several primary sources that state that Phillips went to the Creek Agency to find D.N. McIntosh to encourage him to defect to the Union and, by the way, on their way back to Ft Gibson they decided to take the road to Ft Davis, which they knew had at most a few Creeks camping there and was abandoned when they arrived, and they burned the buildings and stores there and moved on. The only suggestion that Phillips encountered resistance is the assumption made in subsequent reports by his superiors who state something to the effect that Phillips drove the Confederates from Ft Davis. Phillips' report merely said he crossed the river looking for McIntosh but couldn't find him and found few Creek men in the area and that he destroyed Ft Davis. The reports and correspondence of Union and Confederate officers in the immediate vicinity mention no encounter, only that Phillips marched through and burned the buildings.
One of the better books, relatively speaking, on the IT in the war is Knight's "Red Fox: Stand Watie's Civil War Years". Even the title annoys me! In my humble opinion, Watie was not a great strategist or military leader. Knight tries to make him sound like Forrest or Mosby which he was not by any stretch. Watie was a great man and a great leader. He did have military successes and was respected by his superior officers. He was very intelligent, a good negotiator, and had many prominent friends in Arkansas. All that is good enough for me without trying to make him out to be what he was not, i.e. a military genius.
I'll close for now. I'm starting to rant! Just compulsively restating what many of you have said before along these lines.
Ken