The converse fallacy is also, I believe, true. "This person knows how to do XYZ, therefore they're smart" (in a more general sense; good at "other games", as it were), is something that took me time to understand to be false.

And I think your last paragraph reflects this fallacy:

> Real intelligence is the capacity for complexity, pattern recognition, and speed of cognition; none of these guarantee either of the two above conditions.

These are criteria I would give to be good at mathematics, not necessarily a kind person, or cultured person, or good team member.

Of course, I may be hair-splitting at what you mean by "smart" (and I'm sorry for that), but I think this is the angle the article is also taking.