|The Great Kangxi.|
Xuanye was a man of two natures. Famed for his calligraphy and poetry, the Kangxi Emperor presented himself to the world as a Confucian scholar but rode and shot as good as any true Manchu. He managed to strengthen the Chinese bureaucracy without weakening Manchu power. Under his rule the Qing economy began its 'efflorescence' despite a major rebellion in Southern China and near continuous warfare in Taiwan, Mongolia, Xinjiang, and Tibet. Because of Xuanye's tireless efforts the Qing line was accepted by the Chinese people and it is because of his determination China's modern borders have their current shape.
The Kangxi emperor was one of the great men of human history. He was also not impressed with Sunzi.
"For in war it’s experience of action that matters. The so-called Seven Military Classics are full of nonsense about water and fire, lucky omens and advice on the weather, all at random and contradicting each other. I told my officials once that if you followed these books, you’d never win a battle. Li Guangdi said that in that case, at least, you should study classical texts like the Zuo Zhuan, but I told him no, that too is highﬂown but empty. All one needs is an inflexible will and careful planning." 
To attain victory all one needs is an inflexible will. "Inflexible will" is one way to describe the Kangxi's schedule:
"Admittedly there has to be a limit to the work that any one person can do, and when the Ping-yang prefect, Chin, boasted that he could handle seven or eight hundred items of business in one day, I demoted him, saying: “I’ve been ruling for forty years, and only during the Wu Sangui rebellion did I handle five hundred items of business in one day. Nor did I myself hold the brush and write the documents, and even so I could not get to bed until midnight. You may fool other people but you can’t fool me.” In other military campaigns there were sometimes up to four hundred memorials, but usually there are about fifty a day and it’s not too hard to read them, and even to correct the mistakes in them." 
More interesting is what the emperor studied while actually on the campaign trail:
"Before we moved against Galdan in 1696 I told the senior officers—Manchu, Mongol, and Chinese —to meet together by Banner and discuss how we might anticipate Galdan’s movements and how we should deploy our own troops. Even the most casual suggestions were to be collected and reported to me. After the basic strategy of a western strike from Ningxia and a central strike from Beijing across the Gobi was agreed upon, the Council of Princes and High Officials worked out the details of rations for soldiers and servants, fodder for camels, the number of carts, and so on, basing their figures on an estimated 10,790 troops in the western army, and 8,130 in the center—with four horses, one servant, eighty days’ basic rations, and an extra two pecks of rice per month for each active combatant soldier (with the exception of the gunners, two of whom could share one servant).
For my part, I reviewed the campaign instructions of my ancestors’ victories and combined them with the demands of this new campaign.” 
In his campaigns against the Zunghars Xuanye valued his Manchu ancestor's campaign instructions far more than the words of the ancient Chinese strategists. He was not the first to belittle the Chinese strategic canon. In China snubbing Sunzi is itself a veritable military tradition.
Wrote the Grand Historian two millennia before the Kangxi's day:
“Huo Qubing was little given to idle talk. But he possessed great daring and initiative. The emperor once tried to teach him the principles of warfare as expounded by the ancient philosophers Sun Zi and Wu Zi, but he replied. “The only thing that matters is how one's own strategies are going to work. There is no need to study the old-fashioned rules of warfare!” 
Many of China's greatest commanders would dispute this. For every Huo Qubing of Chinese history there is a Cao Cao, who treasured the Sunzi so much that he wrote his own commentary for it.
But there is an important difference between men like Cao Cao and Huo Qubing. Cao Cao's greatest enemies were Chinese. He spent his days fighting other Chinese warlords and the kingdoms they created. They were the kind of enemies the strategies of the Seven Military Classics--written for the most part in a vicious world of Warring States--were designed to defeat.
The authors of the Sunzi never saw a steppe horde. Such a thing was beyond their imaginations. Yet this was exactly the kind of enemy many Chinese generals spent their lives trying to defeat. Huo Qubing and his flying cavalry columns fought their way to fame in the wars against the Xiongnu confederacy of the Northern steppes; the Kangxi told his generals to ignore China's strategic canon while campaigning against the Mongols of the Zunghar Khanate.
The authors of the Sunzi and the other military classics operated under the assumption that those who would read their words would be warring against a bureaucratic state that fielded large armies of free-holding farmers led by professional generals. Their stratagems reflected these assumptions; these strategies could prove disastrous when these assumptions did not match the enemy Chinese soldiers faced. The advice to not totally surround enemy soldiers and force them to fight to the death makes a great deal of sense in the conditions Sunzi and company envisioned.  This same advice is ruinous when fighting steppe hordes who have no land or homes to protect and are masters of the strategic retreat. As long as an avenue of escape is possible, the nomads could not be defeated. To defeat a nomadic army is to surround it, surprise it, and slaughter all of it without offering hope of quarter or escape. 
This is an irony of Chinese military history. In many ways the Chinese strategic tradition better equips Chinese statesmen to deal with the challenges of the modern, 'multi-polar' world of today than it ever did equip the statesman of the traditional Chinese world order.
 Jonathan D. Spence. trans and ed. Emperor: A Self Portrait of Kang-hsi. (New York: Alfred A Knopf). 1974. p. 22
 Ibid. p. 6.
 Ibid. p. 18.
 Sima Qian. Records of the Grand Historian: Han Dynasty II. Translated by Burton Watson. (New York: Columbia University Press). 1993. p. 177.
 This is a formula that appears in all of the Seven Military Classics, but perhaps most explicitly in section five of the Sima Fa. Sawyer, Ralph. The Seven Military Classics of Ancient China. 2nd ed. (New York: Basic Books.) 2007. p.149.
 A point made by David Graff in "Strategy and contingency in the Tang defeat of the Eastern Turks, 629- 630," in Nicola Di Cosmo, ed. Warfare in Inner Asian history (500-1800). (Leiden: Brill). 2001.