I got that quote from Volume 1 of Freeper Jeff Head's Dragon Fury series books. Another translation goes
"All warfare is based on deception. Hence, when able to attack, we must seem unable; when using our forces, we must seem inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near."..
or in my copy of The Art of War..
"Warfare is the Tao of deception. Thus: Although you are capable, display incapability......"
Therefore, if you feel that is incorrect and/or philosophically *stupid*, take it up with Jeff Head and/or Sun Tzu. Have a nice day.
Neither Jeff Head nor Sun Tzu advocates child abuse on FR with an erroneously translated quote for a tagline.
Your tagline errs by inappropriate literalism: the general case was translated as an absolute "all war is..."
In point of fact, if your own army vastly outnumbers an poorly defended, weak foe, the best and easiest thing to do is to simply let the enemy see the truth of the hopelessness of fighting against you, and then show up prepard to fight. In this way, you will achieve victory at minimal cost.
Philosophically and ethically, which is how Master Sun is generally understood in modern times, the statement as you've quoted it generalizes to, "In every undertaking, one should lie and present a false front." This is stupidity! I'll leave it to you to concieve of a situation in which honesty is advantageous. If you can think of only one such situation, then you have shown the statement to be false, because of the implications of the word "all."
Since I have a translation(Thomas Cleary's) which renders Sun Tzu self-consistent, externally consistent and rational, and since your translations render his words erroneous, I do not find that I have a conflict with Master Sun, but with others' interpretations of his work. Since Jeff Head has done a great deal of work, and since I have never seen him claim absolute perfection, I think he probably erred here. But, as you've shown, this error is common to several translations, so I'd say it's a very small error in a large body of good work.
Have a nice day.
Smarmy, catty, passive-aggressive twit: have a bad day of anxiety about your wrongness, then correct your thinking and have many nice days thereafter.
See? Deception vs. honesty, this little exchange might be a good object lesson for you.