We artificially restrict new players to only being able to play on two out of six islands (I've been playing for almost 8 months and still only get 2 nobles), if both of your nobles are on the same island, then you only get to experience ONE of the six.
I don't know how you can have a discussion about character density and not address that you have a lot of players that would love to play on more than one or two islands, but you are preventing them from doing so.
This is a huge part of the problem.
