What do western doctors think regarding the value of herbal healers?

How do they practice. Physicians are trained utilizing evidence based medicine in which outcomes are documented and proven. We are trained with a strong understanding of the pathology and physiology of disease and the human body from a scientific perspective in caring for the whole patient. We are looking at reproducible outcomes with a strong understanding of how and why. If herbalists can do this, they are welcome.
Caution. Proceed with caution as some things may be harmful but there is a benefit to be had in certain scenarios.