I looked at his chart for a sub 2hr 50min marathon, your volume seems about right. Esp during wk days. The only thing you’ll find is every other wk, volume will get slightly longer each wk till one is running just over race distance in the LONG RUN.
Very good book on Low Volume.
He even has Training charts for those wishing to break 2hrs 38min! Much like CF’s charts on S-l and L-s for sprinters.
A bit about Jeff (from his book) - After competing at olympic level 10k, he started a program involving more rest and less weekly mileage, couples with a long run every other week and at the age of 35 ran the houston-teenneco marathon in 2hrs 16.