Thought of an idea of having a dungeon that can be beaten in many different ways. it would have a 8 person party and its up to the party what classes they want to bring. you can have a standard party with 5 dps or maybe a party with 1 tank, 1 healer, 4 dps, 1 bonatist and 1 alchemist. there were unspoiled nodes in the dungeon and items that could only be crafted within the dungeon. a bonatist can harvest a vile that a alchemist can turn into a poison, this can help kill the boss with 3 dps as fast or maybe faster as 5 dps lets say
or maybe a miner can mine some stone to be crafted by a blacksmith into a weapon only in the dungeon to help kill a swarm of mobs.these crafters and gathers cant freely get to their unspoiled nodes or craft their items, this generates a lot of threat and must be protected by the party, prehaps bring a second tank to help control the aggro.
this setup would bring all the classes together and give the players total freedom on how theyd like to beat a dungeon