Those are good points. You're right I'm describing a fairly rare kind of hire, and a solid process must take into consideration the reality that not everyone is that strong or interviews that well, yet may have other highly valuable traits.
Perhaps an appropriate measure for interviewing is to do some psychological profiling to spot where a candidate is imbalanced, and then incorporate into the remainder of questioning. As an interviewer, you're always going to be biasing towards your own strengths and downplaying weaknesses, and although there are personalities that pose more or less danger to others, there isn't a perfect personality overall.