John Locke was the most important thinker to live in the Baroque period because he founded the tradition of empirical study. This became the basis of the modern sciences; especially psychology. One of the most important fields of modern psychology is the study of the brain's cognitive processes - called sensation and perception. These two terms describe how people first sense something in their environment, and how that is synthesized further in the mind. The study of sensation and perception has not drastically changed since its birth, with John Locke's Essay Concerning Human Understanding (1690). The main point I am trying to make is that John Locke was much more than a philosopher, like Descartes. He was a man who made contributions that were essential to the formation of all modern sciences.
So the main question is then: which type of reasoning is more important, deductive (Descartes, obviously) or inductive reasoning (Locke). It seems pretty obvious that inductive reasoning led to the modern social sciences, but would Locke's inductive reasoning have come about if Descartes wouldn't have asked such profound questions? Descartes was the first to ask such profound, deep questions; he arguably started the Baroque philosophical movement. Locke, meanwhile, lived during the Baroque, but contributed to future progress much more than Descartes did. Therefore Descartes might have technically been the most "Baroque" thinker, but Locke was definitely the most influential on future generations.