Certainly, that's a good suggestion. A word of caution though. While it is possible to create AI traffic for unsignalled routes, it doesn't usually work, and shouldn't be done for ActivityGenerator templates. It can work with "scripted" activities if you know exactly when the player will be where, so the traffic can route around the player.
But single track w/ passing sidings is no problem. Usually I just run the player down one track and the AI down the other (of each passing siding). I did a few of those with the Clovis tutorial. Sometimes you can use the "Begin Passing Path" feature, it works on some routes but not all.
Thanks for the suggestion and for taking the time to watch the tutorial!
Happy Railroading,
Steve