I listened to an interview with Joel Spolsky from 2011. He made some interesting points about this. If you have 3 people you have 3 lines of one to one communications. If you have 4 developers you have 6 lines and it starts getting difficult So what he prefers is to have one person responsible for all communications. Everyone communicates through this person and by the time that person has 5 developers to communicate with it's a full time job.