Many years ago had a similar problem - backyard, kids after school and weekends teasing and threatening my dog. Invited a friend to bring his 150 lb mastiff over a few days when school bus came -little did the kids know the mastiff was a darling, but looked menacing, but it had a huge bark and out weighted every one. Could stand up taller than the fence or the kids. Didnt bark much. Only took a couple times and the kids changed their route home.
