It might give a useful heuristic in fields where success is strongly multifactorial - if you aren't at least doing well at each sub-factor, don't bother entering. It might not work so well when there's a case that success almost wholly loads on one factor and there might be more 'thresholds' for others (e.g. to do theoretical physics, you basically need to be extremely clever, but also sufficiently mentally healthy and able to communicate with others).

I'm interested in the distribution of human ability into the extreme range, and I plan to write more on it. My current (very tentative) model is that the factors are commonly additive, not multiplicative. A proof for this is alas too long for this combox to contain, etc. etc. ;)