Hi BR,
Brian's point is really about C2, not about whether the aircraft are too expensive to risk. Whatever the risk management methodology used in Vietnam, it seems that the end result was that the high risk of certain missions was passed to Air Command (or whatever it was called then) in Canberra. This is clearly unacceptable.
In a similar situation today, the risk would be held by the Joint Task Force Commander, who could make decisions about tactical risk based on his read of the situation. It may end up being a person of the same rank and service, but that person would be responsible for the outcome of the mission as well as the aircraft and crews, and will have a better perspective on the level of acceptable risk.