Hi everyone, thanks for the replies.
Okay, so I tested out swapping my king for someone with a good education traits when educating children. I've got mixed results but there seems to be a pattern of the child picking up a better education trait the earlier you swap out the educator. But swapping out the educator without giving enough time for adjustment might lead to a worse education overall. What do you folks normally do?
First test - Indulgent Wastrel king. I gave the child to a Midas Touched the exact day before she became 16. Result - Amateurish Plotter?
Second test - Fortune Builder. Gave child to a Midas Touched the day before he became 16. Result - Indulgent Wastrel (...)
Third test - Fortune Builder. Gave child to a Midas Touched at the beginning of the month before he became 16. Result - Fortune Builder
Fourth test - Fortune Builder. Gave child to a Midas Touched three months before he became 16. Result - Midas Touched
Fifth test - Fortune Builder. Gave child to a Fortune Builder three months before she became 16. Result - Fortune Builder
I know it's not a scientific series of tests - in addition, a couple of these kids were the exact same kid, just reloading the game. But I guess next time it will be a good idea to transfer the kid to a top-quality educator about three months before they turn 16, or after they receive a trait in their 15th year in the hope that they are unlikely to gain two traits in the same year.
So what makes the ideal educator? Apart from MrHuman, of course. In order of decreasing importance, someone with of the same or desired culture, a top-tier education trait, as high stats as possible, and hopefully without any teachable good-for-nothing traits?
In light of this, I think I will have to review my education policy slightly for my other courtiers, to favour people with top-tier education traits instead of just looking at raw stats. Apart from making sure that my good breeding stock isn't turned chaste or homosexual (or homicidially ambitious).