Not the same reason, as it is better to practice one hour every day of the week instead of seven hours on one day because of the sleep you have.
To complete the argument about learning: you play the tough section, correcting a few errors. Then you go away for a bit, and during that period the brain updates its hardware to include those corrections. The mistake is to hammer/saw away repeatedly and interfere with what you have already achieved, wasting time and effort. I think the OP kinda acknowledged this by recommending switching at whim between different tasks within a practice session.