Problem with not having a plan and winging it

Okay, let me first preface this with the thought that we don’t have a leader in this group. Our group was created with the intention to perform the Fishbone and no other reason. So that being the case, we have no director or coach. What does this mean? We are rehearsing strictly with the idea that the tools and skills we learn in rehearsals will be used to do this form.
Positive – our form has a very simple idea at it’s core for us to follow (we follow the cause and effect of something from one scene directly into another and explore how it affects those new people and their relationships) which makes it easier to incorporate the skills and tools into it and see if it works.
Negative – because we have no coach it becomes a problem of what our focus is supposed to be and when that’s forgotten it takes a herculean effort to get back on track.
Problem – we have rehearsals and when things have been less structured, things have veered off course and sometimes things get personal (never good).
Opinion – I am of the opinion, if we have no coach, we need to have a group focus (much like with what we have to do in a group scene.) Without this group focus, people will do and say whatever they want in the name of change for creativity and growth. Which is a bad joke.