Not quite the same as what you're doing, as this was a MTB race, but if you look at the results from 24 hour in the old pueblo and see how the teams managed their laps:http://www.epicrides.com/results/24resu ... Index.html
I think with a 24 hour race like that, especially during the night laps, it's really going to be up in the air about who feels good and who doesn't. Who gets to sleep, and who keeps going. Of course there's always solo riders who keep going non-stop the entire time too, so if everybody has the legs, then by all means keep rotating. As others have mentioned, the key really is to have someone out on the course at all times. With 4 people riding with a 3 hour break in between I think you could cycle everybody in order pretty easy without any downtime. Of course you could always go with the Breaking Away
strategy and just put your best rider in pretty much the entire time.