The Game of Thrones - Problems?

I've enjoyed reading the many volumes of George R.R. Martin's magnum opus (?) A Song of Ice and Fire. What has spoiled my enjoyment at times though is the relative lack of understanding of the author of certain basic elements of the very Earth-like and human-like world he has created. I mean that is really his get out of jail card in some respects. He can always argue that he is not writing of the Earth or humans but some other alternate reality.

Nevertheless, here are just some of my issues with it:

-1. Languages. The author makes a big deal of all the various languages of the realms he writes of; but for all intents and purposes the "Common Tongue" appears to be English. The various devices he uses in rhyme and names only make sense in English and cannot pertain to another tongue. I cannot name any examples but when I come across these devices of language that are supposed to be in some other "Common Tongue of Westeros" they can only make sense if that tongue were indeed English. Now there's nothing saying that an alternate reality or alien world might not have developed English or a very English like language but the question always plays on my mind and takes away from the experience.

-2. Broadleaf trees, or really any trees in extreme sub zero climates like the lands beyond the wall. The author at times talks of broadleaf trees that are surviving amongst the bitterest cold of the Northern lands. This is just an impossibility based on both the temperature and light requirements of such organisms. It is no surprise that any areas in the arctic circle can barely support grasses let alone trees. This is one of my biggest gripes with the descriptions of the North.

-3. Sell-sword companies that have been in existence for centuries. Seriously... a company of 10,000 like the "Golden Company" who are exiles and descendants of exiles from Westeros who have simply floated from battle to battle for coin is truly beyond all belief. If wealth is what they are after then it belies belief that such an army of men would be stateless. I mean the first thing they could do is simply overthrow a city or three of people and begin a nation of their own with all the wealth it contains. Are these men totally without needs for women and homes. Children? I mean it makes no sense at all since the company would have extinguished by the death of its original members long ago if it can't recruit constantly. How do they carry all the wealth of hundreds of years? Yes the author says they have gold arm rings and so on... but really I think if you had an army of 10,000 the first thing they would do is form a nation out of lands they conquer.

Anyhow, there are other things and I'm sure you all can probably name some others, but these are some of the ones that I think make the book rather weak in my mind. Compared to other SF fantasy worlds, and I am thinking of Dune here, whose author has a greater understanding of the human psyche and societal constructs and where few if any holes can be found in the underlying logic of the constructed world ASOIAF fails, perhaps understandably as it does attempt to enliven a huge and complex world. GRRM betrays some of his simplistic and shallow understanding of these things when he blunders like in the examples above.