It's an internal conflict because Sarah has to decide whether or not to confront her friend. Internal conflicts take place in a person's mind. It shows conflicts of the character with her own self. In these text, Sarah's mind is conflicted whether to confront Connie or not.
I would actually use them together: benefit from someone's expertise.
For example,: While building this bridge, we could benefit from the architect's expertise.
or:
Let's invite Sarah, she knows a lot about cooking, we could benefit from her expertise!
