Nope, the math doesn't work that way. That's only true if you're predicting the odds of a particular variation. Since there are many possible enhancements, there are many possible successful variations, and hence the odds of producing something useful are higher than you indicate here. Which, BTW, is also one of the critical flaws of the article we are ostensibly discussing here.
The math just doesn't work. And as you acknowledged (you now tell me in a moment of weakness), arguing from extrons doesn't work, because incremental changes are very likely to be harmful, and because it is very difficult to see (even conceptually) how there could be a path of helpful or at least benign incremental changes leading to a somatic change of any significance.
Yes, very likely to be harmful. But every once in a while, it can be beneficial. It doesn't have to be often, and it really isn't - once in a million transcriptions, there's an error in transcription, and once in every million errors, it proves beneficial. Given time, that's enough. Given enough time, what seems impossible really becomes inevitable.
One of the greatest discoveries in the 20th c has been the discovery of DNA, and the full implications of that discovery are still being absorbed. I would predict that future historians of science will say that the existence of DNA showed that Darwin was largely wrong (though in an interesting and helpful way).
If anything, I think it's quite easy to demonstrate that molecular biology has confirmed the basic outlines and structure of Darwinism by showing the fundamental interrelatedness of all life on earth. You have to go back a long, long way to find the common ancestor that you share with the oak tree in your yard, but the evidence for such a common ancestor is right there in your DNA. And the tree's ;)
A few posts back, you gave a little rehash of the ancestry of the human species, but you didn't address the central point, which is why roughly 200,000 years ago homo sapiens sapiens came onto the scene with a brain much more powerful than hunter gatherers needed. Think about this--99% plus of that primitive crowd had brains capable of reading, but alphabets had not yet been invented.
Alphabets are one of the many side-effects of evolution. The evolution of the hominid brain conferred advantages to the holders of those brains, of which alphabets are only one. Part of basic problem-solving is the ability to engage in abstract reasoning, to think about and consider contingencies other than what is present in the immediate moment. That is, the ability to comprehend past events and draw patterns and conclusions from them, and to consider future events in light of past ones. I don't know about you, but to me that sounds an awful lot like what writing and alphabets are all about. ;)
Given that, why is it so hard to think that alphabets were an inevitable result of brain development?