The 3rd slot for dps is useless. I used to play a certain MMO that has the tank, 3 dps and healer style... Usually you wait over 30mins as dps in that game too, longest wait was 5 hours for a 5-man dungeon In FFXIV it is usually 15-30 mins as dps with high level roulette taking 5-10mins to get in. Usually I spend my time on dailies, alex farming, crafting, leveling another class or chatting with my FC etc while I wait in que, so time isn't wasted. When I am in a hurry I will just que as healer to get my daily roulettes done