It is not the content that makes characters complex, but the arrangement of that content. We all know people who have one-track minds or are so aligned as to be completely predictable (and often, therefore, boring!) People who are more diverse contain conflicting or dissimilar traits and are much more interesting to be around. So it is with characters.
Imagine building characters to be like playing Scrabble. There are a given number of letter tiles, no more, no less. The object is to create words until all the tiles have been employed. The game won’t feel “complete” if any tiles are left over. Now imagine a set of words that are all the same length and use up all the letters so none are remaining. Suppose there is only one combination of letters that will accomplish this. If we build characters that way, we get the one and only Archetypal set. There’s nothing wrong with playing the game that way, but after a few zillion times, seeing the same limited set of words over and over again wears pretty thin. It is much more interesting to create a wide vocabulary of all kinds and sizes of words.
From the Dramatica Theory Book