It is worse and this advice is much broader than it seems. The general concept applies to trying to capture any well-defended position. So it applies to trying to win your bosses job, winning a married person away from their spouse, going the customers in any market that is well-served, and so on.
Sun Tzu defines an opportunity as an opening, a position that no one else has occupied that has certain advantages. We advance our position by moving into openings, not moving into opposition. His entire method is built around identifying openings.,
As Sun Tzu says, a general that fights and wins a hundred battles in not a good general. A good general finds a way to win without fighting a single battle.