Grishka writes:There are two kinds of folk song arrangements:
As separate works of art, usually by named composers such as Grainger, Vaughan-Williams, Britten.
As mere renderings of the song, the harmonies / accompaniment sounding folk-like, as if improvised. (Some folk traditions actually include fixed harmonies; the traditional rounds may be viewed as the only English contributions to that category.)

This seems a mite prescriptive to me, but perhaps I am misunderstanding the intention.
Is there nothing between the classically based work of RWW etc and a "mere rendering"?