As I have said several times the problem is that the game allows 'super' Guilds to be formed. If the game would somehow limit the number of top players or the power of a guild it would force the formation of more that one guild that could compete in Guild wars. It is probably too late to do this because of braking up the guilds now will probably cause a lot of players to leave since one of the reasons they are staying is the interaction they have with their fellow guild members in the chat.