Once a group is together they take it in turn to sperform their summons. Most group will be for lesser summons, and tend to be between 3 and 5 man groups. Each Twlight camp has 2 lesser windstones, and so a group can use one, sell Final Fantasy XI Gil to the other and then kill some mobs until the next spawns. Though it might seem a good idea to head to another camp this poses two problems. First of all, the combat bug prevalent in Silithus prevents some people from mounting up, and the group could be split up and attacked by all sorts of nasties on the way. Second, you have to consider that other groups may be summoning, and that running all over the place hogging windstones isnt so fair for other groups.