WRT your last point, I didn't read the conclusion to say that GRRM maliciously cause harm, but through his incomplete knowledge of history and his assertion that the culture he portrayed was historically accurate was causing harm. He simply noted the deficiencies of GRRM, and the resulting consequences of such.
And to the point that you've brought up about a difference between this article and the last 2, I would counter to say that all three have had the same conclusion, that GRRM has been inaccurate with the portrayal of horse-bourne nomads, only here he has laid out the consequences that it entails. If you're fine with the predicate but have issue with the conclusion, I would suggest you make a counter to his argument, otherwise it would appear to be in bad faith to lambast his conclusion yet agree with his predicate and have no word on his argument.