Then Paul applies the command for vigilance to the elders' oversight of the flock. Notice three things here that are very important for our life as a church. First, the church is like a flock of sheep in need of shepherds. Second, the elders are the shepherds. Third, it is the duty of shepherds to care for the sheep.
Pastors are the shepherds being spoken of here.
They aren't separate people or separate rolls. And in the New Testament, churches always had more than one elder or pastor or overseer. A one-pastor church is unknown in the New Testament. This is true whether the churches are small and new or older and large. Not just the healthy sheep, but also the sick.