Markers of RE papers need to be aware of religious and non-religious responses to issues. With the best will in the world, a committed Christian must value the Christian response above other responses and must award marks accordingly.
I had understood that people who marked exam scripts should be teachers, and should have experience of teaching the subject to students at the relevant level. In no way can vicars be regarded as teachers, since their job is to promote a particular world view, not to explore alternatives with children.
They can hardly be said to have experience with the age group, since the majority of churchgoers are older people. Nor can they be said to have experience working with people of a wide ability range across the social spectrum, as the Church of England tends to attract the professional middle classes.
Vicars are no more suited to marking GCSE RE than bookies are to marking GCSE maths - both having some professional interest in the subject, but neither having a full grasp of all aspects of the subject as taught and learned in school.
10 Vallenders Road
Bredon, Tewkesbury, Gloucestershire