Both Mike & Rojo, valid points.
With reference to Mike, the bureaucrats could get round the argument that everyone doing the same job would get the same pay, (to comply with equal opportunities), but it would be supplemented with a "local weighting" to take into account variations in regional costs. Just like the existing High Cost Area Supplements, Inner london, Outer London & Fringe areas.
Rojo, also correct! Foundation Trusts already ignore guidelines agreed under Agenda for Change, by producing hybridised jobs with "salary scales" which fall outside the agreed national bands.