One of the greatest strengths of the Star Wars Expanded Universe has long been its adherence to the concept of a single (more or less) ironclad canon, in which all works are considered to be equally true and valid and any addition made to the franchise must respect those works which came before it and, in turn, must be respected by those that come after.
In terms of constructing and maintaining a logical and consistent vision of events occurring beyond what was covered by the films, it is almost impossible to heap as much praise upon this approach as it deserves. To tie together so many stories on such a scale, written by so many different authors over the course of so many years, it can be said with certainty that no comparable franchise exists. That is not to say, however, that there are no sacrifices that come with a system as strictly regulated as this one.