Hat's off to anyone, Scott, who takes on peeling potatoes with a "birds beak" paring knife!
Going back to the "three knives" though, I'd suggest this knife should replace the suggested, straight[ish] bladed paring knife in the essential three.
The Naniwa stones certainly come with a nice range of grits. They also look as though a certain amount of practice would be useful to avoid surgically skinning your thumb. Are they perhaps designed for, ahem, knives we aren't talking about here, like pocket knives.
Maybe a potato peeler should be added as "the 4th knife"