It's possible though that this is analogous with running. An IQ test could be seem as a relative sprint whereas the business of solving genuinely complex problems might be a marathon.
A 'sprinting test' may actually provide a rough gauge of general fitness and physical ability - and in so doing be a rough predictor of marathon performance in the general populace. But at the higher levels those with fast twitch muscles are actually at a disadvantage in a marathon against those with slow twitch muscles. Extrapolating the sprint result to the marathon only works at the very crudest level.
Of course I'm not saying this is actually the case with intelligence but in certainly could be.
I think you may be able to hold the accomplishments/time ratio constant while varying the quickness of thought. However, the quickness of thought that I'm talking about may be different than what the article is addressing.
For example, in a math class it may take me a while to comprehend each step that the teacher is taking which makes me lag behind the rest of the class, but given enough time to fully understand everything, I can outperform the average without too much trouble. So it can be in the way that I attack problems. I slowly and methodically learn about all of its parts until I finally comprehend it all and then conquer it relatively quickly, whereas others may quickly learn about something but have to repeat the process a few more times to get it to sink in.
Maybe this kind of slowness has nothing to do with the speed at which nerve impulses travel, but it sure doesn't help with job interviews.
But even then I suspect that a quicker thinker with similar experience would be able to accomplish even greater things in that same period of time.