Well it turns out this chart is in my paperwork for the Stag AG110. The color chart in this thread may be a repo from that information...that doesn't matter. So it seems its an actual Buck document.
I do see an issue with positioning on the chart. I think that anyone that looks at this chart will read it as showing improving overall desirability (as a knife steel) from left to right. Clearly S30V is the best knife steel on that chart, we all know it. I took a swag (pulled out my trusty ruler) at the total point values shown. I came up with 196-154cm, 198-HC, & 203-S30V.
So each bar is given equal weight and value. Sharpenability seems subjective. Well it is a stretch for me to rate 420HC higher than 154CM as a knife steel. Maybe the guys at Buck will shed some light on the positioning and if they are really trying to say to the world that their 420HC is the second best steel on that chart.
Buck isn't trying to say that 420HC is better - they're just being honest about the fact that it is a little bit more corrosion resistant and easier to sharpen. Regardless of what us steel snobs think, 420HC is a great steel - it makes a fine knife blade that holds a good edge, re-sharpens easily, polishes like a dream, and is consistent and relatively easy to manufacture knives out of. This chart is not intended to show a clear ranking - it is meant to break down the 3 most relevant characteristics of the steel for the consumer so they can choose the steel that suits their needs most effectively.
The 'point' (no pun intended) of a knife is to cut things. Therefore, if you had to rank sharpenability, corrosion resistance, and edge retention, I would imagine most people who their time on dry land would rate Edge Retention highest. If you were a commercial salt-water fisherman, you might rank corrosion resistance highest. Hunters who like to be able to re-sharpen quickly partway through skinning an Elk might rank sharpenability highest.
S30V and 154CM are steels that focus on edge retention. Yes, they will be a little harder to sharpen, but under prolonged use, they will stay sharp and cut better for longer. Some have pointed out that they can be a bit brittle at times. This can be true. If you need more shock resistance, you may want to check out some non-stainless carbon steels - they exhibit these kind of properties. Stainless steels have always been a compromise - we give up a little performance so they don't get rusty just sitting in our pockets.
In a manufacturing situation, they often end up get ranked by cost and difficulty of manufacture (in addition to performance). But the general rule is that as performance goes up, so does difficulty of manufacture. S30V is the most expensive as a raw material, and it is the hardest on Buck's grinding equipment. It eats up grinding wheels and sanding belts faster because it is tough and wear resistant. 154CM is a little cheaper and a little easier on the equipment. 420 is cheaper still, and a lot easier on the equipment, but it's not
that much worse at holding an edge. If you were looking for the best bargain, 420HC would be the champ all day long. If you want better edge retention, go with 154CM or S30V.
I dont care about any charts 
