there's plenty of places to overtake and the first 5 or 6 miles or so was land rover tracks so you can sort placings out by the 1st singletrack climb. By the 10 or 12 mile mark the people you are riding with you will generally find will be riding your pace all the way round.
Beware not too spend too much time at feeding stations though, mine will be 30secs to 1 minute refilling maximum. Keep your legs moving all the time is the key