Geography and Logic of Brain

What sense does it make for some functions to be localized in some parts of the brain? Does brain follow any 'geographical' sense - cold near mountains, less oxygen at high altitudes, hot at equator, one type of vegitation in one type of soil etc. That means, although some parts of the brain perform some functions but why only that region? And what significance is there for that region to be performing that particular function?

Do neurons follow any logic or there are just random connections common to all? Like we can't have head near feet and arms at back or fingers 10 ft. long, then why does it seem from so many researches and empirical evidence that brain doesn't have any logical organization of neurons? I wonder many times whenever I read a fresh article or chapter about brain and some of its function, I come up with finding new areas and connections which do not seem to be compatible with my previous knowledge and other information. That means neuroscience is discovering areas of brain responsible for certain functions, but are there any explanations that why some areas are specialized for certain functions and what significance does this hold in the architecture of brain in relation to other areas?

Same areas are found responsible for many different functions and vice versa. Why can't brain just make some sense, when it comes to situating higher functions? Why can't just one type of soil be found in one particular region and not others. When complex nature and its geography follows patterns, why not brain. Is it that we have still not found a proper 'map' of the brain still, to be able to make any sense in its 'geography'?