Yeah-- the one thing that I could ALWAYS count on from DD was reading. At least half of our "homeschooling" activities were "read ______."
I also gave her daily LISTS for school-- that way it wasn't ME verbally TELLING her what to do. A sample list from age 6:
-- Do problem 48 in Challenging Math Problems workbook
-- Complete pages 23-27 in "Complete Science" workbook
-- Read Ch 16 and 17 in Caddie Woodlawn
-- Read what you like! (Please put finished books into the book box)
I have to be honest here and tell you that this was not ideal in terms of developing written expression (which she resisted), but it saved my sanity somewhat.
I recorded what she read. When she was six, she read
thousands of pages a month. Many thousands, actually-- like 4-8K. I just tried to sprinkle reasonably good historical fiction, classics, and non-fiction her direction, and that DID more or less work. Her attention span wasn't the problem.
She was different from your guy in that she could be still for HOURS.