The phrase "excellent herders" means that someone or something is very good at gathering and directing a group of animals, such as sheep or cattle. Full definition
They're also excellent herders of sheep and cattle, one of their original jobs as an all - around farm dog. (dogtime.com)
They are also excellent herders and do well in search - and - rescue operations and drug detections. (pethelpful.com)
The result was not only an excellent herder and guard dog, but also a breed that would outdo others to be courageous, intelligent and healthy. (blog.oliverspetcare.com)