This is pure intuition but I think pastured rabbits would do better with other animals around than without. My thinking goes like this, let's say you have 100 rabbits on a fenced pasture, a fox breaks in, kills as many as he wants before getting bored and leaving (yes, predator animals are known to do this, they won't stick to killing the one or two they can drag off to eat, for some reason). 100 rabbits and 30 ducks on a pasture, fox breaks in, ducks freak out and attack him, driving him off before he can kill many rabbits. This combined with small bushy trees for cover from aerial predators and I think it becomes a viable system. A bunch of rabbits in an open field is like a buffet for wildlife.
Something in my gut tells me, sheep ducks and rabbits. It feels like they belong together. You get everything you need animal product-wise, wool and milk from the sheep, eggs and feathers from the ducks, meat and pelts from the rabbits. Well, meat from all 3 really but mainly from the rabbits; they give you the most meat per pound of feed of any mammal or bird, if I remember correctly. Also the rabbit and duck manure
should be enough to fertilize the land so you can shovel the sheep manure off to be used elsewhere. To me this brings it back to the ideal of 1:1 farming despite the having to grow a patch of sunchokes or something for rabbit food elsewhere.
Well, that's my vision anyways and the first thing I will try once I start raising livestock. Sort of a 3 sisters garden but with animals, that's how I think of it. Sheep graze the grass and leaves, ducks eat the bugs and weeds (a pond would be included ideally, a pond is like a duck food petri dish), rabbits you grow food for since they're such excellent feed converters. And none of them are a threat to the others as far as I'm aware. Having a ram or two around might even make the predator animals think twice about breaking in in the first place.