I want to smoke what you've been smoking.
When I ran distance, total weekly mileage was key, as was the distance of the weekly or bi-weekly long run. I am delighted to read the stories of people who've done a marathon on very little running but it's not something I would choose to do as a training strategy myself. FWIW, I've run a half-marathon 3 times in my life, all nearly 40 years ago. Training for my first marathon is what turned me off from running - I was just too bored logging that kind of mileage, especially being outside for the required lengths of time in all kinds of weather - and I therefore never completed that "pretty short distance" myself.
-S-