I guess so, but that's what I mean: The article's meaning depends on one's view. To me, C = inevitable disaster, A = inevitable success, and B is everybody else. With three grades/classes, that's as far as I can get. You have to keep the "A"s happy and prepare for their exit. You have to get rid of the "C"s as soon as you've identified one and given them their fair chances. But I think that your A-B-C scale only addresses those who I consider "B"s, as "A"s and "C"s are mostly immune to management technique.