How imperfect can land sparing be before land sharing is more favourable for wild species?

Two solutions, at opposite ends of a continuum, have been proposed to limit negative impacts of human agricultural demand on biodiversity. Under land sharing, farmed landscapes are made as beneficial to wild species as possible, usually at the cost of lower yields. Under land sparing, yields are maximized and land not needed for farming is spared for nature. Multiple empirical studies have concluded land-sparing strategies would be least bad for wild species provided land not needed for agriculture was indeed spared for nature, but the possibility of imperfections in the delivery of land sparing has not been comprehensively considered