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.
