One of the reasons why business owners hire Business Advisors is because the Business Advisors have the ability to look at their clients' businesses from 3 different perspectives.
#1) As "Business Advisors"
They will look on the strategic part of the business. The angle often left behind by the owners. Probably too busy being in the business or they don't have the knowledge and skills to do the strategic planning.
#2) As "Customers"
Most of the business owners tend to ignore the customer's point of view. This leads to their businesses become irrelevant or not up to the clients' expectation.
The Business Advisors themselves are customers to many businesses, which maybe in the same industry like their clients. So they can bring in the ideas, what to do and what not to do in the business. They can even share the suitable business processes , the challenges and many more ideas.
#3) As "Business Owners"
The Business Advisors themselves are business owners. Qualified and experienced Business Advisors will surely able to share with you their own experience in managing business and share the other business owners' experience as well.
By the way, Business Advisors are also part of your external team.
So they should bring in value to your business, not just being there.