Third Party Activity

We very rarely speak in depth about those who are on the outside of the center of an operation or business. Those who may disrupt the flow or even enhance it at times. The third party is sometimes the underdog, while other times being the linchpin. My question is, can we let them act in a mediocre fashion? Do we allow them to dumb down the system and still get paid? Even in relationships, can we let them get a bigger piece of the pie when they have not done the grunt work? How do you handle a third party person? Can they be allowed to just flow as they please? What do you say?