Expect to have a few problems as your dog goes through adolescence. Although some dogs sail thru without a hitch, many go thru an "idiot" stage. Suddenly your nearly mature working dog is acting like a puppy again. It doesn't usually last long. Most of our Great Pyrenees are pretty much settled by the time they are a year old. Males may take a little longer than females.
Different dogs, even of the same breed, can have very different guarding styles. Some dogs stick very close to the goats, some like small areas to patrol and some never stop trying to expand their territory. It doesn't make one good and one bad, however one or the other may be best for your situation. Having a pair working together that complement each other can be very effective.
Feeding the LGD
What and how you feed your dog can have an effect on how well he works. A hungry dog or one with no energy isn't going to be very effective. We use a triangle shaped enclosure made out of hog panels about 6-7 feet on each side and wired together at the corners. One side has a hole cut in it big enough for the dog to get through. Smooth the edges with a file after you cut the hole so it doesn't have sharp edges. A weatherproof automatic feeder that holds about 25 pounds of dog food is put in the corner opposite the "dog door". We use wire or cargo straps to hold the feeder in place. The enclosure is fairly easy to move either by breaking it down or tipping it on its side and "rolling" it to the next field.
The energy requirements of a LGD are high, especially in the winter. We switch to a higher fat dog food during cold weather. The dog food we use for summer has 26% protein and 12% fat. In the winter we use one with 22% fat. By doing this all the dogs maintain a healthy weight, otherwise some get too fat in the summer, others too thin in the winter.
Homework
In order to not make the same mistakes we did, do your homework before purchasing a LGD. Reading is good; talking with people who are successfully using these dogs is better. They will have opinions on rearing, training, breed of dog, feeding, etc. Probably very different opinions. They will have small herds, large herds, large and small pastures, different predators and problems. Try to find people who have dogs working under similar conditions to what you have. They can help you avoid costly mistakes. We could not have goats without our dogs.