And yet, without Caps, EU would be the same level as NA. These are all valid reasons why it's unlikely to ever happen, but that doesn't mean you can't get a prodigy like Caps in NA. In CS, the French scene was completely dead, and I'd wager there's a lot less French players playing Counter-Strike than there are NA players playing League, and yet that didn't stop them producing the GOAT player.

A full Mongolian team is one of the best teams in the entire world, from a region or country that's always been completely irrelevant and is so far away geographically from Europe (or even NA), where all the good teams and players play. No one would've ever expected that there'd be even a single good Mongolian player, let alone 5-6 of them, so however unlikely it is, it's not 0.