A team accomplishes more together than they could accomplish separately. Missionaries are focusing on many more diverse people groups, population segments and cities than ever. Each group deserves a specific strategy. People Teams are the best way to develop diverse specific approaches for so many different peoples.
Teams provide a more intimate way to support one another and be accountable to shared goals.
Teams also provide the opportunity to be more efficient in their work. Teamwork provides opportunities for productivity to be more efficient and effective. People Teams are not just another way to organize work. If teams are just an organizational unit then it will quickly fail. Some teams in the past did not function at their potential because its members were not completely focused on the ultimate outcome.