It should be noted that Cottage Living is NOT a farming pack, but rather a homesteading one. You are not tending to herds of animals and plowing fields here.
Keeping llamas and alpacas is actually an increasingly used method of predator deterrence in the UK to protect hens from foxes, as well as worldwide, where they can protect sheep and goats from coyotes. They instinctively protect their charges against predators without the need for training. Shearing and selling their wool is just an extra and not the primary reason for keeping them.
Here, llamas provide gameplay where sheep wouldn't. In addition, I'm not sure how common it is for homesteaders to keep a single sheep rather than a small herd of them at least.
