Lister,
The scheme is not aimed at the trainee pilot. Training of them is the remit of the flying schools. The aim of the mentoring scheme is to help those who have gone through training and the initial flush of the £100 bacon butty and flying the family and friends. These are generally people who either than lack general direction or are nervous of spreading there wings further.
For example, someone who wants to do that first trip to France but lacks experience in flight planning, NOTAM, customs etc could do the trip with a mentor who would show them the ropes. Or maybe someone who is fairly new out of the training environment and want someone to come with them on a cross country flight to give 1st hand guidance on RT or airspace transits etc.
It is meant to be an informal no cost of helping people keep flying, building experience and confidence.
The LAA Coaching scheme is aimed at largely at teaching, revalidation, differences training etc which is why all coached must be Instructors.