Why frigates were not simply enlarged pinnaces

Were frigates essentially scaled-up pinnaces?

Not directly. Designers borrowed useful ideas from fast, maneuverable small craft while reshaping larger galleons, galleys, and other warships into frigate-built forms.

A pinnace offered examples of speed and maneuverability, but the frigate did not emerge through a simple scale enlargement. Builders instead applied similar priorities to existing larger ship forms. Contemporary language could therefore describe frigate-built galleons or frigate-built galleys before frigate settled into a distinct category. Naval types often evolved through this kind of recombination rather than one clean family tree.