Is there going to be a Guild Rankng system st up soon? If you're going to make emporia more useful, a guild ranking would be a good way to determine who gets the better emporia's although it shouldn't be based on a guild vs. guild pvp system only.
Maybe each guild can have a running total of opponents killed in war, total accumulated dual fame by members, quests where the whole guild can do together such as each member's turn in will +1 Guild Fame, total number of monsters killed by all guild members for the week/month, etc.