[jilko]

Not necessarily. For the record I'm in the camp "they didn't just get lucky," but it's totally plausible to argue that they did.

Taleb does this exact thought experiment in "Fooled By Randomness." He imagines a pool of investors who are weeded out purely by random luck each iteration of some process. You still end up with people that get some insane track records, purely by chance. In fact, he spends quite a bit of the book talking about barely fictionalized people he knew in the trading world whose strategies made money for long periods of time before blowing up simply because they happened to be in the market at the right time.

I suspect the nuance we need to add to OP's comment was "they were there at the right time AND won the iteration game purely by luck." So they were the tippy top of a cohort in a generally advantaged time where their strategy happened to be optimal. Again I don't personally think that's the case (I believe there's something more fundamentally correct in their approach), but it's a totally reasonable thing to argue even in the absence of other examples.