I disagree with INTJ being strategically the smartest. As a group they really don't seem all that smart to me, [MENTION=9310]uumlau[/MENTION] is the exception. In this group on TypeC I would say that he is the only INTJ I would think is smart enough to actually strategize successfully. While INTJ may be the type to strategize the most, I would not include smart into that equation. I apologize if I offend other INTJs.
Funny things happen at the high end of the high IQ scale. Rather than using IQs, let me use percentiles.
The dynamic I see, for example, in the software field, is that you have a lot of people who are very smart, who are easily smarter than 95% of the people around them. I'm not even talking about IQ tests or anything like that: just normal everyday aptitude at work.
The problem I see is something I call "expert-itis". These really smart experts have simply never encountered anyone smarter than they are. Worse, at this high end of smarts, knowledge becomes very, very specialized. It is possible for two people to be experts in the "same field", and yet their knowledge barely overlaps. Part of the dynamic that occurs might be best represented by a Venn diagram. Two circles, each representing the sum total knowledge of each individual, each about the same size. The overlap of the two circles comprises about 10% of each individual's knowledge.
"Expert-itis" as I name it, is the phenomenon of two such individuals meeting, and as one sees that the other person only understands 10% of one's own knowledge, one assumes that the other person is a complete idiot.
The main reason that I see this dynamic fairly clearly is that, like you, I'm in that 150+ IQ range, easily 3 standard deviations above the norm (based on standardized tests, not IQ tests per se), around the 99.5% percentile. I routinely have people who barely understand what I do, who would quickly flunk out of the courses I took, treat me as a complete idiot, because I didn't know some dinky little detail that they consider to be all-important. Yet when push comes to shove, and we have to solve a real-life problem, I would often run into cases where I figure out the solution in 10 minutes, but I have to spend an hour or more "proving" my solution to people who haven't a clue what is going on, even though they are very (95th percentile) smart, and they think I'm an idiot because I don't know some dinky fact that they knew.
I see this same dynamic in people trying to determine how smart each MBTI type is. We understand our own kind of smarts better than others' versions of being really smart. The INTPs think the INTJs are all idiots. The INTJs think the INTPs are all idiots. The reality is that they all have "expert-itis": they see that small section of overlapping knowledge, but they DON'T see that other 90% of knowledge that is full of things they don't know, things that they don't even know that they should ask about.
I think that some of what you note about INTJs and myself is also part of that dynamic. I suspect you don't see the strengths in that INTJ thinking, because they aren't your strengths. You only see my strengths because I'm not merely INTJ, I'm an INTJ with a ton of education and several decades of real life experience backing it up, while a lot of these other INTJs are still just kids in college or barely out of college, still full of unrealistic expectations that were instilled by our kind of weird education system that doesn't actually teach you how to get and keep a job.
So, are INTJs the smartest strategic thinkers? It's definitely an aptitude or talent. And it's a kind of weird one, that looks especially stupid to Ti doms. Ti doms are thinking in terms of logic and logical consequences. INTJs (and Ni doms in general) don't think like that. Instead, they have a tool that is uniquely suited to strategy: an internal library of "how things work". While the topics might be logical/technical, the thought process is not. It's more a process of pattern-matching. If the pattern matches, or at least matches closely, the INTJ just pulls out the pattern, makes a couple of adjustments to handle special real-world cases they're aware of, and then applies it. This is great for strategy because if the facts on the ground change, one doesn't have to figure out the logic all over again (the typical Ti-dom thought process), one just looks for a new match (a very fast process) and works from there. A young INTJ has a much smaller library of such patterns, so the matching is going to be much broader, more naive, more likely to not account for everything and result in mistakes. An older INTJ with significant education and much experience in a specific field will have a very fine-tuned library of patterns. Also the older INTJ will have "meta-patterns", an ability to judge how well the pattern one has just matched might apply, an ability to judge others' levels of expertise and take advantage of them, and so on.
One of my longstanding questions about MBTI has been "what does a stupid INTJ look like?" and "what does does a smart ESFP look like?" I think I have answers for these. The stupid INTJ will still tend to score high on an IQ test, but will be kind of an idiot savant, unable to actually apply any of that knowledge in real life. The smart ESFP will be remarkably practical and high-achieving, yet not appear to be all that smart. (
Famous ESFPs - CelebrityTypes.com ) I bring this up because the real point isn't what type is smart or not, but how each type expresses its own intelligence and/or stupidity.