Because they are famous and I've worked with them, I can make you famous too. Back in the last century, when the world was different, this person helped a speaker who is now well known. Avoid jumping to conclusions about their role. You'll find that many will. Not enough people ask the prospective provider specific questions about this.
People compare the consultant's work to what they knew before.
If a new speaker didn't have any knowledge before, and someone provided them with info that everyone in NSA knows, then to that particular speaker, the consultant is a guru. If you are an NSA member and already know those ideas, then the consultant is just well informed. Call the provider and judge for yourself. Get specific about the role they played. Talk to them about their clients and compare yourself to theirs.