Sanne, thank you so much for your input, lots of good things to think about. I don't think they do clustering in 1st grade but I'm not sure. I think it starts a bit later, like 3rd or so. My son does have a 'best friend' this year and there are several very smart kids in his class. I'll ask his current teacher about the differentiating part and stuff like that.

Can you tell me a bit more about times when you think adding structure doesn't pan out?