For my games some NPCs use called shots and some do not. As the game is played this changes. So yes, sometimes NPCs use them on PCs.
Intelligent creatures in my games each have a map detailing the collection of information they hold in their brains. The game is designed to simplify these across all intelligence forms, creature types, and factions, while retaining a high degree of complexity for each individual. Plus, it tracks changes over game time as the game is played. One of the elements included can be called shots. They are a physical combat tactic like trained men-at-arms having learned how to perform a shield wall to proficiency. Called shots are taken by NPCs according to these scripts as relevant game situations arise. These situations aren't always optimal for odds of tactical success, but they neither are they supposed to be. Wisdom determines and is a rating for the accuracy of NPC mind maps to actions with greater odds of success. More knowledgeable, more Intelligent, and Wiser creatures are more difficult to engage with and are rated as greater challenges because them. Of course, greater challenges offer greater rewards for engaging with them and far from all are in opposition to the PCs.