We've got about 10-12 acres under grass (opposite of what I wanted, but at least we got drought resistant grass planted so we're not using ground water). We've recently switched to Husky Robo-mowers and battery-electric walk-behinds for areas the robos can't do.

If you flip one over, there's a disc with very small pivoting blades held in place by centrifugal force.

We don't mow through May, one pass with our big-ass Kubota diesel, then turn on the robos. It mostly works.

The Huskys can be height-adjusted up to 3.5" - important if you want your lawn to not die in a drought (ours just goes dormant, but still...) as the extra height provides a bit of shade.

We walk the area pretty carefully, looking for sticks, and I've never seen a sliced up animal. We don't have hedgehogs here in New England, but an overabundance of rabbits. Baby ones hunker down, too - but I've never seen the remains of one cut up. I watch for snakes when doing that first cut, and I do see them - and they are at risk from the tractor deck's blades (even at 4").