Experience and Expertise (Performance psychology consulting)

Do you believe a person must have expertise or experience in a domain (eg. business, high-risk environment, performing arts) in order to consult effectively in that domain? Explain the rationale​ for your opinion. What potential negative impact might extensive expertise or experience in a particular performance domain cause? What benefits could extensive expertise have?

References
Hays, K., & Brown, C. (2004). You’re on: Consulting for peak performance. Washington, DC: American Psychological Association.