Will the Circle Be Unbroken?

Our circle is deeply into the Storming phase of Tuckman's model. It's natural, but uncomfortable nonetheless.

One member has approached others about an outside business opportunity, which has created mistrust/distrust.

One member has 'warned' me that he/she is leaving the company and the state sometime soon. This will necessitate exit from the circle.

Because one member has moved into a new role in another member's department, one of them is offering to leave the circle so as to not make the other uncomfortable.

I need to do some research on how this phase can best be managed. Should I become more directive? Should I share Tuckman's model with them? Should I simply listen and coach?