The link has an example of what I'm talking about. The image is 'wrong' by conventions of perspective but not by those of drawing. Since photography cornered the visual reportage end of image making in the mid-C19th there is no necessity for photo like drawings, just as pictorialism was an attempt to give photographs artistic respectability by making them smudgy and impressionistic. There's nothing morally wrong with either approach and as I said previously, it's an interesting experiment but I responded to your idea of 'cheating'.
So long as you're not passing off a tracing as an example of life drawing - which anyone who knew their subject would spot immediately - cheating doesn't enter into it.