Most player groups would not choose to set themselves as an eighteen man party. The current known difficulty scaling is that for every player, Odyssey will add a degree of difficulty. Tyr knows that at the general difficulty level they are all playing at, which is determined by the region in which you start in. Lugiria has the steepest learning curve of any region. This is due to it being the cradle of all civilization, thus hosting the greatest number of secrets. Tyr put them all in a party as it will mean them more exp. Also, they are operating in teams that don't interlap, this also pushes up exp gain. Finally, normal team make up goes: three, five, ten and twenty-five.