Unfortunately you asked more than one question, so I edited out the rest. In Erik Larson's The Devil in the White City, there is a consistent clash of ideas between true geniuses in their respective fields. It should not be surprising to learn that visionaries do not always see things in similar ways or that they are generally unwilling to compromise their vision for the greater good. The circumstances of this event, a World's Fair which must be superlative in every way, required men with all kinds of talents to come together in a united way without the pride and arrogance which generally accompanies such creative and artistic achievers. It did eventually happen, but the process was certainly marked by disagreement and disunity.
Olmstead was a forward-thinking man who designed some of the great parks in American cities, including New York's famed Central Park. He had a scope and vision which few others had regarding the aesthetic--the non-structural--components of the Fair. This could have been a non-confrontational and harmonious endeavor if Olmstead had not believed so strongly that the site and the grounds must be right before the buildings would work. The architects, of course, believed the structures are the foundation and the grounds merely a garnish. Those two views are going to clash on any kind of project, so credit must be given to mastermind Burnham for making it happen. Perhaps lesser minds would have compromised and collaborated more easily, but the conflict between two disparate philosophies held by creative geniuses could not have been avoided.