As for the numbers, sure big agriculture is good with lobbying governments, but the author of the OP article is a relatively well known environmentalist from the UK that did a lot of research on this for his recent book. I find it rather unlikely that these are fudged numbers from lobby firms.

But I also think people are misunderstanding what he mainly says. He doesn’t say that relatively small scale farming can’t on average feed the human population, but rather that our current model of resilience against the natural variability of food production (which is going to get much worse with climate change) is build on a massive overproduction of cheap grains that can be easily stored and shipped around the world.

Unless we want to face massive naturally induced famines again, we either need to maintain this model (which seems increasingly unlikely to be physically possible) or urgently find another way to improve food resilience, and small scale farming doesn’t seem to be able to do so.

And on a side note: brutal conflicts between small scale farmers and nomadic people that are reacting to natural variability of food availability are almost as old as humanity itself, and really not a future I would like to see on a global scale.