Well, this was an absolutely wild ride.
History books of half a century and more ago seem to provide a much clearer insight into what the West, especially in a social sense, was really like—maybe because the writers were a few generations closer to its people; but more, I think, because they had the ability to write both honestly and calmly about the often mind-bogglingly different motivations and mindsets of an earlier era, instead of putting it all through the rigid filters of modern mindsets and continually and neurotically assuring their readers that We Disapprove of All That Now.
For the most part all Sonnichsen has to do is relate the facts, as far as they are known (admitting candidly where it's impossible to know, since different sides tell different versions of the same story), and the simply stated facts are enough to make a page-turning potboiler. But he also frames it with some thoughtful passages that try to sum up some of the root causes of feuding and vigilantism—a strange and fascinating mix of Southern honor codes and the uniquely American emphasis on self-government. A key thing that I've been coming to grasp about the West is that it was not wild because of the absence of law—sheriffs and judges abound in these accounts—but because the legal machinery was often subservient to the particular code of the citizens operating it.
Comparing these Texas feuds, broadly, to the range wars of movies and fiction, one sees how the latter are often way too simplistic, probably because of a need to have a clearly-defined "good side" and "bad side"—and also a need to make the "good" side vulnerable and near-helpless for dramatic purposes—when real-life feuds were more often between two groups of people extremely similar to each other, and equally well able to handle weapons. Also that real-life shooting affrays were far less formally arranged and elegantly choreographed than they were spontaneous and extremely chaotic. But as far as individual incidents within the feuds go, the astonishing assassinations, bushwhackings, perjuries, vows of vengeance, and unlikely survivals could rival almost anything a dime novelist or screenwriter has dreamed up. The telling difference is how the action is often completely divorced from those 19th-century codes and mindsets when put on the screen or the magazine page.
Sonnichsen is a good writer, with a clean enjoyable prose style and a suitably dry sense of humor. I know I'll be revisiting this one and chewing it over as inspiration for my own fiction in future.