The 4-8 range stones are like a bridge that gets you from one side of the river (bevel set) to the other (polishing). The basic idea of honing is to get a bevel established (which by the way you could shave off, albeit uncomfortably) and then smooth out the sides of that bevel to yield a comfortable shave. Smoothing out the sides is a progressive thing, or at least it is quickest and least painful to do it progressively than in one humongous jump. To continue the bridge analogy - you might be able to jump the river in one leap, but it can be wide and it is way easier to take the bridge.

Having said that, if you have patience and a reasonably fast-cutting 4K stone it can be used to set bevels off even junky ebay razors - I used to do that for quite a number of years before utility overcame my stubbornness and I bought a 1K stone...

James.