This is somewhat related to the application of strength to various sports and physical endeavors. Most sports utilize strength to a large degree, but it's usually in a narrow application, e.g. a golf swing, a sprinter's run, a rock climber's grip. The naive algorithm to improve at these sports is to practice them, and the slightly less naive method is to train for strength in that narrow application, for example you often see rock climbers training by doing rock climbing specific grip exercises.

Unintuitively, strength is a general adaptation that applies to all specific movements. A muscle is either strengthened across a range of motion, or it isn't; a muscle cannot be strong swinging a club while not strong lifting a weight, nor can it be strong holding a rock while weak holding a bar. It is optimal for most sports to train for general strength via barbells, and then to practice that strength via the sport. The rock climber should do heavy deadlifts and chinups to train his grip (and everything else), not special rock grip exercises, for the latter are difficult to progress in small increments and are inefficient in a time sense. A man who can do chinups with 150 pounds hanging from his waist, and who can hold a 550 pound barbell, will not have a problem hanging onto the bouldering wall; he need only practice his technique.

To the article's point, you should get "strong" in everything until you decide to practice that strength in one thing.