In projects, I typically help out with 2 things:
  1. Making things look pretty
  2. Lifting the story, making it bigger
I rarely do major surgery in fixing the flow of a story (this is where all time was spent when writing McKinsey documents). In a short 20 minute pitch the sequence of the messages is usually more or less right. What I see often though is that people do not pitch their story big enough, they take out the big picture of how their solution can really change things in a fundamental way. For you, the expert, it is obvious, for the outsider it is not.