I have both llamas and goats, and have had them for years.
Llamas we use for pack animals, guards, fiber producers and pets. They are trained to picket ropes so we can stake them around the yard and use them for "weed whackers". They do a good job of keeping weeds and brush trimmed and under control.
For goats, I originally had a dairy herd. I used to milk 12 goats, twice a day, by hand. Then I got fiber goats - both cashmere and Angora. Now I have Boers, which are meat goats. I also have them trained to picket ropes and use them for cleaning up around the fence lines, and since goats thrive on stuff that most animals won't eat, they are excellent at reducing weeds.
I also have a couple of alpacas, which are very charming animals.