It's true that most cattle farms are on the small-end, and have plenty of land for their cattle.
It's also true that the vast majority of cows slaughtered for meat come from just a few industrial feedlots.
Changing the way that "most" farms work might change how much methane truth A cows produce, but the vast majority of cows are truth B cows that aren't impacted by the decisions of small-time farmers.
There is not enough land on this earth to allow for free-range cattle at the rate humans consume them. The solution isn't to do it more efficiently, but to stop and do something else. Ford said people would ask for faster horses, and 100 years later we have people wanting cows that fart differently.
It's the cheeseburger you want, not another magic chemical added to the lovecraftian nightmare that is factory farming. The way to reduce the impact cows have on the environment is to reduce the number of cows bred for food.
This is a good article, I would add to the key takeaway is that methane production from animal husbandry is mostly a closed system, the greenhouse gases being produced by cows are being absorbed from the atmosphere. atmosphere -> photosynthesis in grass -> cows -> atmosphere -> grass etc. So reducing herd sizes doesn't reduce net carbon in the atmosphere.
Looking at the net carbon paints a very incomplete picture. The effect of methane is very different from CO2, you might describe methane as 30x as powerful a greenhouse gas as CO2 is.
The other factor here is that agriculture drives deforestation, which releases sequestered carbon.
I've noticed that changing my own diet by eliminating animal products has cut down significantly on methane production in my own gut.
My farts literally don't smell like anything at all anymore, when a small one used to clear the room with ease.