In reply to pasbury:
Yes, I agree, it's a tricky one. There's a similar stretch of flags on the other approach to the PyG trig point (from the top of the scramble up the Big End on the route up from Bracken Bottom/Pennine Way) that was flagestoned a couple of years ago. It's grassed in beautifully and the peat erosion that was there previously has pretty gone.
There used to be a whole load of stabilisation fabric/material on the route up Ingleborough from the Hill Inn (around Humphrey Bottom) for years and it deteriorated rapidly and presumably couldn't take the footfall. Now it's mostly flagstones there too, with a similar results.