This is a good place to stop focusing on the term Search Engine Optimization and to start talking about Internet Marketing. Search Engine Optimization is only one aspect of effectively selling your product or service on the Internet. Your success hinges on the cooperation of people from many disciplines. One of the primary reasons efforts to improve Internet sales fail is because of a lack of cooperation from management deciding what they want to tell the customer rather than concentrating on answering a customer's question or solving a customer's problem. And if you're lucky enough to have a potential customer visit your website you have a few seconds to get his interest, or the customer clicks ways.
While all pages are important, search engines place the most importance on the home page. The home page is valuable real estate. Every discipline in the company competes for this tiny space. It's even worse because most people will not scroll until they become interested. So you have the space above the fold (or what you can immediately see when you lad on the page) to play with.
No matter how honed the consultant's people skills may be there is a high probability that an honest Internet marketing consultant will get everybody upset. That's why success stories are few and far between.