This thread is pointing out to me the idea of balance between the three faculties.
For instance if our feelings are particularly strong regarding something, that may suggest a need for gathering more information (sensations, input). Thinking in these terms, self-interested agents gain power through disrupting the balance of the faculties. For instance religion minimizes (undermines) the sensations and perhaps the prolepses by insisting on "faith." All that leaves is feelings with which to measure truth. And reason, which is ineffective without proper input. The same goes with filter bubbles. Or Platonists: look at the society Plato proposed in the Republic.
No wonder we have to struggle so much to understand our natural faculties....
Very insightful post, Godfrey ! I think balance is a very good way to put it. The idea of the three-legged stool does in fact seem to be a good metaphor for the Canon. I know that's not original to Epicurus, but that idea of balance and working together seems appropriate.