And still Skyjob gave you an excellent reply encapsulated in the first sentence.
The guide is good judgment and common sense as made by any given individual on any given day. Any discretionary call is balanced against a whole raft of influential factors. Captains are promoted based on significant assessment of their ability to make good judgment calls in difficult circumstances. It doesn't follow that there is a prescriptive formula. Each situation will be different, and different individuals may well make different calls based on their own experience and judgment.
"What if" scenarios are fairly meaningless without a broader and complete picture into which to place them. Even then, there is often no "right or wrong" answer.