Cattle can feed on land that is not suitable for growing crops
Our problem isn't tetris with land. We have way, way, way more land to produce food crops than we need to feed everyone, we don't need to optimize for the few places where we can raise a few cattle exclusively. We can feed the same amount of people using far less water, land, and power using a vegan-ish diet.
growing cattle keeps the land from turning into concrete. If you actually want to conserve land you want to use as much already deforested as possible for growing crops and then never deforest new land. Slowly you should work onto getting conservation NGOs to integrate it into government protected land.
Seems to me like a fools errand to optimize land use. The optimal use in the Americas for example was likely already there 14,000 years ago before humans arrived in Americas. We obviously can't go back, but we can improve land, but optimal ....