thanks for the appreciation.
So one example of a firm that really knows their stuff in a particular field is Horváth & Partners. I used to work for them and still know a lot of people there. They are among the best, probably even the best, when it comes to Controlling, Management Accounting etc. Would I hire them for such a topic? Definitely. Would I hire them for a strategy project? Most likely not.
Similar things can be said for LEK (M&A, Due Diligences), Simon Kucher (Pricing) or Management Engineers (acquired by Strategy&).
Then there are sector specific boutiques, like Berryls for Automotive or zeb for banking. They have incredibly deep sector specific knowledge, but would probably be lost on a project for lets say a media company.
The caveat for a relatively junior person is: If you join one of these firms, you are committing yourself relatively early on in your career. That is perfectly fine if you know that you want to stay in that field, but it can make switching later on harder. But you can really build strong knowlegde in a certain field relatively quickly.
As you might notive, I did not mention any bad examples, and I will not. I have a couple in mind, however. But as a general rule: If the list of covered industries and/or functional specialties is longer than the list of partner / MDs, that company does not have focus ;-)