Here is a way to look at coaching and therapy that might be helpful:
It is quite possible to function highly in one domain (work, romantic relationship, family, etc.) and less highly in another. I also assume that how "highly" one is functioning is not an innate trait, but something that can change over time.
There are types of therapy and counseling that are more goal-oriented (e.g., solution-focused therapy) than others, and I believe that what these therapists do can look a lot like coaching. This is one reason for the overlap between the clouds.