Sometimes I’ve got asked to help with, let’s say Kanban or Scrum or something else. I’m always very curious at those moments. I haven’t seen an organization having the goal of implementing Kanban or Scrum inside. To me, those are solutions. Or tools. To get your organization where it wants to be. That can help in solving your real goals. Uncovering those goals is a very important step.
So I see Kanban and Scrum and many other methods/frameworks/mental models as tools that help you improve your organizational design, so that it could serve its purpose better.
So, I’m not going to “just” help you with Kanban. I’m going to uncover the real need behind it, and if Kanban (or something else) could be a good solution for that need – then for sure. But not Kanban, for the sake of a Kanban (even though I more often hear such requests around some other framework).

I see a lot of spirals (or circles if you wish) in the development of some areas of knowledge. It was very much an all-around consultancy in 199x-200x. Focus/popularity shifted a lot to coaching in 201x. So, coaching seems like new hype. Obviously, when working with an organization, the two mentioned above are not the only choice. There is also a place for mentoring, facilitation, teaching/training, etc.
I should admit, my default (initial) stance most likely would be coaching. It is safe. It is not going to harm your organization. Later on, when knowing and understanding more about you and your organization, I may choose other stances as well. I would be as clear as possible on the role (or stance) I’m currently in, to avoid any possible confusion.

Overall, while working with an organization I could bring valuable help, I do not think my intervention is always required. It is not a must. Basically, most organizations potentially could get there by themselves. My intervention could make it faster.

As an external consultant, I think there are two areas where I could bring the most value.
The first one is systems thinking. Helping you uncover important relations within your organization – something that you could hardly see from within (being part of the system), could be easier for me to reveal from the outside using my experience working with many organizations.
The second one is exposing you to potential solutions. In other words, showing you some tools that could be helpful in solving your problems.

However, choosing which challenge to start with or which tool to use, in the majority of cases will still be your choice and your responsibility.