You could think of it as a two hundred mile dual sport, with a lot of paperwork.
Mostly, the stages are short enough that there isnt enough time to pass, youre through the stage in a matter of 10-25 minutes, and if the guy behind you would have to be going significantly faster to catch up to you, if you start a full sixty seconds ahead. If your average speeds are with 5 mph of each other, you'd have to go over twenty miles before you made up a full minute on the guy ahead, unless something goes awry like a getoff or wilderness exploration, or run out of gas
Yes you can often re-seed yourself if someone behind you is consistently faster.
Just ride the first one to have fun, and get used to the time cards and volunteers, and see how the whole thing shakes down admistratively. By the end of the day you'll have figured out the deal.