I think the point of the article is that whether or not someone is an A-player is context dependent. Alice might not be an A-player at TechCo (for some reason e

I think the point of the article is that whether or not someone is an A-player is context dependent. Alice might not be an A-player at TechCo (for some reason e.g. the way they dole out projects) but is an excellent fit at MicroCo, where she is considered an A-player because she can work well in their context. Whether or not this works in practice is obviously a bit iffy, since finding someone who fits exactly your context is incredibly difficult.