I find that when considering piloting tasks, pretty well everything can be boiled down to the prime directive: Aviate - Navigate - Communicate. With the possible exception of the last, in certain flying environments, a pilot must otherwise have the capacity to keep the responsibilities of all three of these disciplines handled relative to the needs of the flight.
Aviate is the least tolerant of the three, if being ignored for any length of time, so we have to keep an eye on that one most, and foremost. That said, in a busy traffic area, Navigate will become very important.
I watch myself, and other pilots, deal with the workload demands of these three, and how they are balanced. Different pilots thrive best in one, but not all of these three disciplines. So, they are best to be well aware of their shortcomings in the others. In some cases, a pilot can avoid, or minimize exposure to certain flying environments, and thus probably not have to call upon those lesser skills. In the long term, that pilot should be focusing on improving the lesser skills, but in the immediate term, create an extra level of safety by recognizing the shortcoming, and making extra allowance, preplanning, flight manual review, or whatever is going to be necessary to keep the swiss cheese holes from lining up.
The problem can come when a pilot fails to recognize that an unexpected change in conditions could drive workload in one or more of the three disciplines, way up, fast. Does the pilot have the excess capacity to handle it? If you think you don't you put some mitigation in there in advance to help you out should the worst come to the worst.
For what I have seen, it's not so much the super skilled pilot who survives, but the super prepared pilot. No matter how much skill, something which you had never considered, or prepared for, is going to get you.
My three most common and scary have been icing conditions - so I stay out! Errors in weight and balance for aircraft I am to fly, but did not load, so I check those really carefully, and improperly accomplished maintenance, so I do really careful maintenance reviews and walk arounds.
JFK Jr. just did not imagine how little there is to see when you're pointed out over the Atlantic at night, and how fast that type of aircraft will build up speed when you fail to control your attitude. Neither condition would have been fatal, were the other one to have been very well handled. The third hole in the swiss cheese? Two women aboard who really wanted to get there, and no self discipline to say, "No"