I've got certain issues with the VOTP series, in that it fragments many earlier collections (albums) that were given over to individual singers and compiles the songs according to category rather than singer...generally I lament the umbrella approach taken on VOTP which I regard as ever so slightly patronising too...

I can't see why the approach taken by Topic to VOTP is patronising. They've simply chosen to organise the songs by category rather than singer which is their privilege. You would have preferred that the songs were organised in a different way. Fair enough, neither is right or wrong, just matter of choices. But I fail to see how they are being patronising simply because they have chosen a different way of organising their material.

... and essentially misleading as an ethnomusicological document, which, of course, it isn't.

In which case that statement is irrelevant to your argument.

... Even the original records are very selective in that respect; one wonders how much stuff was overlooked to give the right sort of impression.

If you have more material than you can fit on a record or series of records (or CDs) then you have to make choices. Are you sure those choices are made to give a particular impression or simply to illustrate the variety of material, or just chosen because they represented the best songs and/or performances by the particular singers?

The truth is, you don't know and are simply speculating and trying to then fit your speculations into your particular world view without providing proper evidence to support your view.