Here's a though, what I might do if I was High Emperor and Ruler of the World and all its subsidiary companies.
Instead of Super Six, have RW Challengers. Basically anyone can join, all they are required to do is to follow one of the variety of training plans that RW has written specifically for the London marathon. Nutrition tips, how to remain injury free advice etc, would be given online. On the day the Challengers wear a special RW Challengers shirt. Anyone can join.
At the end we all see how many people hit their target.
Voila, a good platform for RW to justify their generic training plans. Just as much if not more publicity on the day and MORE people get access to training and stuff.
All the experts have to do is offer their sage advice on the forum.