My recollection is that von Clausewitz didn't advocate total war and unconditional surrender, but used them in examples, as physicists use frictionless planes and spherical cows.

https://www.gutenberg.org/files/1946/1946-h/1946-h.htm

BOOK VIII. PLAN OF WAR
CHAPTER I. Introduction
CHAPTER II. Absolute and Real War
CHAPTER III. A. Interdependence of the Parts in a War
CHAPTER III. B. On the Magnitude of the Object of the War and the Efforts to be Made
CHAPTER IV. Ends in War More Precisely Defined—Overthrow of the Enemy
CHAPTER V. Ends in War More Precisely Defined (continued)—Limited Object
CHAPTER VI. A. Influence of the Political Object on the Military Object
CHAPTER VI. B. War as an Instrument of Policy
CHAPTER VII. Limited Object—Offensive War
CHAPTER VIII. Limited Object—Defence
CHAPTER IX. Plan of War When the Destruction of the Enemy is the Object

> "As in war the want of sufficient exertion may result not only in failure but in positive harm, therefore, the two sides respectively seek to outstrip each other, which produces a reciprocal action.

> This might lead to the utmost extremity of exertion, if it was possible to define such a point. But then regard for the amount of the political demands would be lost, the means would lose all relation to the end, and in most cases this aim at an extreme effort would be wrecked by the opposing weight of forces within itself.

> In this manner, he who undertakes war is brought back again into a middle course, in which he acts to a certain extent upon the principle of only applying so much force and aiming at such an object in war as are just sufficient for the attainment of its political object. To make this principle practicable he must renounce every absolute necessity of a result, and throw out of the calculation remote contingencies."

> "The aim of war in conception must always be the overthrow of the enemy; this is the fundamental idea from which we set out.
Now, what is this overthrow? It does not always imply as necessary the complete conquest of the enemy’s country."

> "In the preceding chapter we have said that, under the expression “overthrow of the enemy,” we understand the real absolute aim of the “act of war;” now we shall see what remains to be done when the conditions under which this object might be attained do not exist.

> These conditions presuppose a great physical or moral superiority, or a great spirit of enterprise, an innate propensity to extreme hazards. Now where all this is not forthcoming, the aim in the act of war can only be of two kinds; either the conquest of some small or moderate portion of the enemy’s country, or the defence of our own until better times"

He even mentions deconfliction:

> "If this influence of the political object is once permitted, as it then must be, there is no longer any limit, and we must be pleased to come down to such warfare as consists in a mere threatening of the enemy and in negotiating."

> "This kind of idea would be indispensable even if war was perfect war, the perfectly unbridled element of hostility, for all the circumstances on which it rests, and which determine its leading features, viz., our own power, the enemy’s power, allies on both sides, the characteristics of the people and their Governments respectively, etc., as enumerated in the first chapter of the first book, are they not of a political nature, and are they not so intimately connected with the whole political intercourse that it is impossible to separate them? But this view is doubly indispensable if we reflect that real war is no such consistent effort tending to an extreme, as it should be according to the abstract idea, but a half and half thing, a contradiction in itself; that, as such, it cannot follow its own laws, but must be looked upon as a part of another whole, and this whole is policy."