Jomini vs. Clausewitz in Civil War writing

Though both Baron Jomini (the author of The Art of War) and Carl von Clausewitz (the author of the even more enduringly influential On War) had the Napoleonic Wars as their primary experiential and analytical points of reference, the two theorists are generally presented in the Civil War literature as having opposing views on the operational and strategic direction of armies. On countless occasions, Civil War readers will be told that Jomini favored operations aimed at fixed points of strategic significance while Clausewitz counseled generals toward focusing their efforts primarily on annihilating opposing armies. Presumably, most of these modern writers would concede that that contrast is an oversimplification of more complex theoretical constructs, but you still see it as almost universal shorthand in Civil War publishing.

Yesterday, I wrote about Timothy Smith's Early Struggles for Vicksburg. Right off the bat, Smith describes the period covered in the volume (the overland expedition down the North Mississippi railroads and amphibious assault just north of Vicksburg at Chickasaw Bayou, both abject failures) as a Jominian-style approach of the kind that his boss, US Army General in Chief Henry Halleck, favored. He contrasts that with his view that the indirect approach subsequently employed by Union forces in the campaign (specifically during the long period beginning with the movement down the right bank of the Mississippi and ending with the triumphant Vicksburg siege and surrender) represented an example of Grant's adaptive genius transitioning toward a more Clausewitzian (and less by-the-book) manner of war that, in this case, proved a stupendous success. Smith's assertions prompted me to briefly revisit my own reading of Jomini. I also have a copy of what is considered the best English-language version of Clausewitz's On War (the one edited and translated by Howard & Paret), but it's been sitting on my shelf unread for years.

Back in 2015, curious about how accurately or not Jomini's views have been condensed in the Civil War literature, I read an unabridged 2007 reprint of the 1862 J.B. Lippincott edition of Jomini's The Art of War (see my comments posted here). In it Jomini constantly reminds readers that war is more art than science, and the "rules" of war presented in the book need to be flexibly applied on a case by case basis. Quoting myself in the paragraph third from the bottom: "On the Civil War debate over whether fixed strategic points or enemy armies should be the true target of operations, Jomini believes the proper course to lie in between, with circumstances particular to a given situation affecting the balance."

So where does this wide impression among modern Civil War writers that Jomini was more inflexible on the matter of strategic points than he was in his own words ultimately come from? Is it from the Jomini-influenced writings of nineteenth-century West Point faculty and students [ex. Halleck (in Elements of Military Art and Science), Thayer, or Mahan]? I don't know. Any thoughts?