My point was that it is not just about speed, but about "bandwidth". A simple mind can't wrap itself around a complex problem no matter how much time it spends. Solving a complex problem is more about processing huge amounts of data simultaneously. That's why programmers like to work at night; They have to build all the complex logic inside their heads before turning into code. One interruption from a coworker or spouse and they lose focus and have to start over again.
A simple mind could have unlimited time to complete an IQ test and never get past some of the more complex parts.
From my experience, many incredibly intelligent people will make a problem more complex than it is. They lack the ability to take a common sense approach to solving a problem. Not all, but a good majority do.
That brings us to what a "complex" problem really is. Not all problems have a mathematical basis, but then again, is that what is complex to you? It ma be complex to some and not to others. The level of intelligence may not come into play as much as the life experience one may have to work with.
I have spent most of my career working with and around programmers. They cannot be shoe horned into one paradigm. I would say a poor choice to establish your point. I have known very few to actually work as you suggested they do, which does not mean there are some who do work that way.