Its rare that I run into someone who is smart (not necessarily brilliant) , who can understand a problem space and who can find a path of greatest payback and least resistance (80/20). I more generally run into two kinds of people in product design - mediocre and brilliant. The brilliant people are more dangerous than the clueless. The mediocre can usually only do so much damage as they are slow moving. The brilliant though can produce reams of design work and if it get's implemented then a behemoth is created - a monster project that eats everyone in sight as it grows or dies a slow painful death killing vast of amounts of resources along the way .
For example, in a simlar way, during local mountain bike orienteering race the 3rd rank national road racer was beaten by some local joe bikers, not because he couldn't read the orienteering maps, and certainly not because he was weaker. He was the most powerful competitor in the race by far. He lost because of his unbridled power. He overshot the marks by so far when he made mistakes that he lost the race.
The road to winning design lies between mediocrity and unbridled brilliance.