"Yeah, you're going to have some trouble finding people with exactly 14 in all mental stats, I predict, given Cheliax's current state of gathering statistics on its population. Even if you can find them by checking with all the wizard academies where they measure that, paying to Teleport people in sounds quite expensive." (The back of Keltham's mind also notes that this proposal is something a not-too-competent Conspiracy Korva might float, if their world secretly had much better stat-gathering and/or cheaper Teleports, and they hadn't fully updated on the fake world not having that fact true; and Conspiracy Alexandre might be trying for a hasty backpedal there.)
"But let's leave that aside for now. Let's also leave aside that people with all 14s may have differences that aren't just about the mental stats, like, maybe they came from richer families and ate better as children and got better 'nutrition' and that's part of why they're smarter now. Maybe they have smarter parents and their parents owned more books, or better books."
"Leave all that aside. We test 5 people with all 10s, and 5 people with all 14s. 2 out of 5 people with all 10s get it in five minutes, 3 out of 5 people with all 14s get it in five minutes."
"What have you learned? What do you now believe?"