Sure, but the high school, pop science and TV explanations of relativity and the universe rarely consider anything apart from the two trains travelling toward e

Sure, but the high school, pop science and TV explanations of relativity and the universe rarely consider anything apart from the two trains travelling toward each other, nearing C, with an observer aboard one train. People can grasp that relatively easily, along with doppler explanations of red shift. Every decent attempt to take a step or two further is to be approved. :) When tracks start moving as well it gets mind bending, and no longer intuitive. Now we have multiple scenarios where the combination of track movement (universe expansion), and train movement result in it being "obvious" you have to exceed C somewhere, which we're told is impossible. Otherwise how can the distances end up where they are. It's between these two points most non-physicists stop as it starts to feel deeply contradictory.