It’s generally thought that teachers know everything and consultants know nothing. When you learn from a teacher, it’s through that you’re learning what they know. And when you get help from a consultant, you’re supposed to know that they are basically just project managing things, but they don’t really know more than you do.
The reality is that both follow a similar approach.
Teachers typically use others’ materials as the basis for what they teach. What you‘re getting is 1) their help with your understanding of the materials, and 2) their interpretation of the materials.
Consultants, similarly, use original materials. There are many “third party” research companies that produce studies, recommendations, etc. Like academic materials. Just having access to this is not sufficient. You need a “teacher” to be able to fully use the materials. Consultants help you 1) understand the materials, and 2) figure out how to implement the recommendations for your organization.
All too often, teachers are supposed to know everything, and consultants are thought to know nothing. In reality, teachers and consultants, good teachers and consultants, are much more similar than different.