Remember that each individual has their own outlook, talents and skills, and will in some way be able to contribute positively to the group. The difficult task is often to determine exactly which area that is in. This can become apparent with time, so allow all members equal opportunity to speak, and remember that their contributions are at least as valuable as your own. Groups tend to work best by consensus, though some form of direction or leadership is often helpful in consolidating ideas and ensuring schedules are met. There will be a set number of tasks to be accomplished before the job is done, and an effective group is able to quickly identify those tasks, allocate suitable people or subgroups of people to achieve them, and then tie the project together with the minimum of time, effort and fuss.
Conflict is fine within a group.
Disagreements are usually fruitful, highlighting different points of view and approaches to problems. A group that never disagrees probably only has one person doing anything. However, conflict and disagreement have to be handled well if they are to achieve anything useful. People have a right to their opinions and to have them heard. They can only expect to persuade others if they can argue convincingly and logically, rather than by sheer volume and insults.