"2. Routing
Something you can use to tackle the routing complexity is to place your source files in the same path as the canonical URL. You only need routes for generated content, like index pages and such."
Thank you! The only saving grace for a Gatsby site I recently did was it leveraged a template that did that automatically. To say that it dramatically simplified things is a gross understatement.
Template for those interested: https://github.com/18F/federalist-uswds-gatsby