This article is about using alpaca wethers (gelded males) as livestock guardians in Australia. I had a phone call a few months ago from someone on the East coast asking about using alpacas as guardians because someone on her farm was afraid of llamas because of their size. I told her to buy two alpaca geldings and use them together as guardians.
The main problem with using alpacas as opposed to llamas as guardians is that alpacas are at a size disadvantage. However, most predators will back away from a challenge, and my alpacas (even my pregnant girls!) will challenge stray dogs and coyotes. The advantage may be in numbers, however. I still recommend that people get two alpacas because they don't seem to bond to other livestock the same way that llamas do and get lonely without another alpaca. However, according to the article, they still bond to the flock and will protect it.
I think this is a great use for gelded males who might not have the best fiber, especially the assertive ones. I am certainly going to use this article as a marketing tool for my fiber males.