Here the pastors have soiled the Tabernacle, and their flocks are scattered. In this verse, God says that the pastor's have destroyed the vineyard. Now, Jeremiah takes a different tack on what he has been saying. And I will give you pastors according to mine heart, which shall feed you with knowledge and understanding. Those that try to control the congregation in their own strength, and not the strength of God.
Sheep are incapable of taking care of themselves.
They will eat poisonous grass, and even if they find good grass, they will eat themselves to death. They will die of thirst if they cannot find a quiet pool to drink from, and they can get lost in a crowd. They have no natural defenses of their own, and that is why they are such easy prey. Sermon focused service. The sermon should be the main focus of the service.