Make the process easier without taking over the process

Some random "Agile coach" shows up and starts talking about abstract concepts and "culture".  A lot of hand-waving but no specifics because s/he says you're supposed to "self-organise".  So what are you thinking?  This coach is obviously just another clueless waste of money who's apparently good at suckering managers.

Alternatively, some random "Agile coach" shows up and starts changing everything.  S/he declares that everything you've done previously is wrong (and stupid) and here are a new set of things that you should do and think instead.  If you ask for rationale, s/he tells you that you should just try it first because you have to learn by doing.  So what are you thinking?  This coach is obviously just another clueless waste of money who's apparently good at suckering managers.

If the coach is too abstract, s/he comes off as useless and incompetent; if the coach is too prescriptive, s/he undermines autonomy.

Instead, coaches are the most valuable if they make the process easier without taking over the process.

To do this, I can think of a few options:

1. Propose a straw man target state that the team modifies to their context.  A good straw man demonstrates the coach's insight into the situation.  Getting the team to modify allows them to take ownership.  The coach is not useless, the team maintains autonomy.
2. Ask insightful questions.  Asking good questions demonstrates the coach's insight into the situation.  That the team still has to come up with the answers means the eventual insight is still theirs.  The coach is not useless, the team maintains autonomy.
3. Do both.

Next questions:

• What's a good straw man? How would you determine a good straw man?
• What are insightful questions? How would you determine insightful questions?