Can I ask why you decided to teach your children so systematically from so young?
Sure! My husband and I both went to Stanford University, where we both felt just average. What we noticed, were that the kids there from academically advantaged homes (children of alumni, children of alumni from ivy league schools, children of Phds, kids who had gone to prep school etc) found Stanford much easier than we did. It wasn't necessarily that they were so much smarter (although a lot of them were), but many of them were just better prepared.
That's curious; some of my core decisions about educating my son are driven from my own experience of feeling I wasn't as well prepared for university as I could have been, but my decisions have gone a completely different way. In my case, the problem, as I see it, was that I hadn't been challenged enough at school - instead of giving me harder tasks (especially in maths), those around me had encouraged my perfectionism. So I went to university with an absolutely rock solid basis of school-level material, but when I finally got to a level where some of the work wasn't easy for me, I had no idea how to deal with that situation and felt the universe was broken! Took me years to get back on an even keel. It would have been far better for me if I'd gone to university with some gaps in the prerequisite knowledge but with experience of getting through somehow when I didn't understand something. I determined that my DS should always have problems that were hard for him, including things he couldn't do, no matter how good he was at something, and not too much direction; I want him to struggle a bit and to know that that's OK. Before he started school I was very happy he should work at whatever he was interested in in the way that preschoolers do; I stepped in to influence his maths when he started to complain that what they did at school was boring. In fact this was part of why I positively decided not to teach him to read (even though I knew my mother had taught me) - when he was a baby, I had a vision of this being his first experience of struggling with something and getting there with effort, and that seemed good. Of course in the event, he doesn't remember not being able to read, but I tried!
The bottom line is surely that we do what feels right in our families, influenced by our experiences and whatever else we find to assimilate. One of the things I find interesting about this place is the different decisions people make.
