I think cattle are fine... though I'm also okay with more Bison, goats, sheep, deer, elk, etc. I'm also more than okay with less use of feed lots and direct butchery of grass fed ruminants.

As for marginal land... personally, I can only handle mostly eating meat and eggs, doing much better with ruminants. I'd be just fine with the majority of uninhabited lands being used by mostly wild ruminants over any kind of farming, especially farming that is using chemical fertilizers and stripping the land.