well all a matter of opinion, yes they are good, but in my opinion no better than Nick Dow., or Chris Foster.all a matter of taste or opinion
I do remember an album by Pete Castle , particularly an unusual arrangement of Lord Bateman.
Davy Graham was influenced by the Morrocan Oud, have you heard his recordings and work with Shirley Collins
In fact Davy introduced Martin Carthy to Dadgad and the Morrocan OUD was responsible for Davys choice of DADGAD.
I do not hear anything that is very different from some other uk English folk revival musicians AS REGARDS STRUCTURE OF ARRANGEMENTS