If I were in charge of 5000 missionaries, I would employ both the strategies of Unreached People Groups and Harvest Missions. Incorporating both strategies would lead to the greatest success and demonstrate commitment to the Great Commission found in Matthew 28. 

I may send half of the missionaries to already reached countries. These countries would mostly be urbanized and the cities in them would act as hubs for the missionaries. Like the Apostle Paul, they would “[stay] in key urban centers and [teach] in places of public discussion” (p. 173). Since these areas already have Christianity established, the missionaries would have teammates to work with and the number of believers will multiply due to discipleship, offering a promising outlook for the future. Perhaps this endeavor would create even more missionaries to carry out the Great Commission. Indeed, that is how the early church grew under Paul's missionary advances. 

I would send the other half of the 5000 missionaries to countries where Christianity is not established, or they would go to unreached people groups within a reached country. This means we would have to look at both the regions of Christianity and regions without Christianity as well as the people who have or have not been reached with it. Our goal would be to empower these missionaries to establish leadership in these regions so that they may function the same way as Harvest Missions. It would be their responsibility to equip “[God’s] messengers regardless of gender or ethnicity to proclaim His sovereign power and grace to the nations” (p. 207).