My experience with consulting companies like McKinsey is that they pull things out of thin air when they lack the required knowledge, and use their customers as

My experience with consulting companies like McKinsey is that they pull things out of thin air when they lack the required knowledge, and use their customers as beta-testers. Due to a lack of knowledge/skills and failure to admit a mistake was made within management on their client's side, those interactions are in most cases wiped under the rug of damage control.