I think the boys are learning a lot of very interesting skills, but I think they would struggle a lot with becoming lawyers and doctors like the author claims.
My biggest concern would be their reading skills, and later, their advanced math skills.
He says they read fine, but reading is something that must be done almost every day for years to get to a highly literate point. Literacy and reading comprehension are essential skills to navigating the modern world.
I am just not sure what kind of jobs or careers they will be prepared for later on.
I mean, it sounds great and I would love to have done a lot of this stuff as a kid, but I just see issues if the parents don't really stay on top of it.
If you grow up hunting, fishing and farming, you don't exactly prepare yourself to be a doctor, lawyer or engineer.
On the other hand, if you have the reading and maths skills, you can still be a hunter/fisher/farmer.