It is hard for those who want to argue for principled pragmatism to argue their case. How can I say to a preacher who is faithful and godly but just out of date, who is not strategic, who is dull? After all, God's Word will do its work, won't it? It is not our power, but God's Spirit that builds the church.
I had a little thought that may contribute to the case for principled pragmatism: the gift of evangelists to the Church. If all you needed was God's word faithfully taught, then all you would need is teachers. But Christ chooses to give evangeslits to his church as well.
Isn't faithfully teaching God's word enough? Perhaps you could say that in a sense even God doesn't think so. He chooses to give people uniquely suited to bringing his word to the world.