Even supposing that it is possible to devise a course of action that we have good reason to believe will be effective, there is still a huge gulf to cross when it comes to putting that into action given current political realities.

This depends partly on what sort of "course of action" is devised, and how many people are needed to put it into action. Francis Bacon's successful spread of the scientific method, Louis Pasteur's germ theory, whoever it was who convinced doctors to wash their hands between childbirths, the invention of the printing press, and the invention of modern fertilizers sufficient to keep larger parts of the world fed... provide historical precedents for the idea that small groups of good thinkers can sometimes have predictably positive impacts on the world without extensively and directly engaging global politics/elections/etc.