Hard disagree on that. The image of aligning your toes with a starting line is what makes sense. By contrast, while you may use a line to pull something behind you, it's never the line itself that you're towing.
Towing the line, like you are helping to pull along the message. And towing the line like you are carrying around the lines of the message. It's too good to give up for some oddly abstracted analogy about running a race.