I demand you give me that book... I need to know how to win 40-1 battles like the polish.
Eh, the Art of War is just a book of military common sense, and not a how-to book. It tells you what's sensible, but it's up to you to apply that common sense. Sort of like a book on morals; the ability to discern what principle is in each problem and set a priority is needed to appreciate the book.
Even after that, some of his principles are being challenged. Most notably on encirclement, Sun Tzu advocated leaving an avenue of escape to prevent the encircled fighting to the death, breaking them easily. But the importance of logistics and the advent of long range weapons has contested this principle. Should a unit be encircled and out of bullets, they could simply be shot at by a distance. What must be judged, then, is the worth of the action.
So really, winning battles is as much common sense as a book. That's what some people tend to get wrong from reading self-help books or the like. You have to apply it sensibly too.
Anyway, specifically to your question I fear Sun Tzu cannot help much in regard to that. Sun Tzu only advocated battle when equal, and attack when five to one;
It is the rule in war, if ten times the enemy's strength, surround them; if five times, attack them; if double, be able to divide them; if equal, engage them; if fewer, defend against them; if weaker, be able to avoid them.
The Polish only went into battle forty to one because ironically, their commanders and statesmen have failed to apply the Art of War. They failed to break the enemy without fighting, the supreme excellence in the Art of War. They failed to go into battle advantageous. That is all against the rules presented in the Art of War.
Just for fun, why did the Poles win? Simple, because their enemy did not know them. They did not know the ferocity of Polish soldiers, or their stalwart defense. That only wins you half the battles, according to Sun Tzu.
Sun Tzu simply advocated knowing when to fight and when not to. Fight when it is advantageous, when the enemy is distracted.
In regard to winning battles, there's no way to win if study is not done. Napoleon said the only way to be a great general is to study the campaigns of Caesar, Turenne, and other Great Captains.
For that, you need sense to discern the lesson from each battle, and a sound enough mind to apply it in the heat of battle.
