For every dungeon let there be an instance to select where all your guild members can join at one time.
-Have the difficulty of each mob scale with the total number of members in the dungeon at that time.
-Have mobs all over the map, use the whole dungeon to place mobs
-Have the final boss appear only after every mob is cleared in the dungeon.
Rewards ?? commendations I guess and all that normal stuff. 60 tokens too.