"So should it have a Roud Number? I've no idea. Steve has to make the decision.".

It's not an easy one. Cecil Sharp gets a lot of stick for having been selective, but would his collection have been improved if he'd included all those versions of 'Grandfather's Clock' he so despised?

I'd guess that Steve Roud is very reluctant to play God by deciding which of a singer like Walter Parson's pass muster and which do not.