Most active competition shooters are skilled marksmen. Many plinkers are not. Competitors make it a point to break their skills down into pieces and conduct skill rehearsals (practice) regularly and correctly, with scored shooting events providing accurate, empirical feedback. Plinkers usually do none of this, but they could.
Let’s suppose a plinker decides one day to set up 10 beverage cans. The deserted quarry he uses as a range happens to have a rail tie on which he can set them, and he stands by a fence post closest to an old oak tree. His only rationale for his arrangement is that it seemed like a reasonable, but challenging shooting feat, and because he happened to have 10 empty beverage cans and a convenient place to put them.