One thing I've thought about is if they just let people switch jobs in dungeons, so the healer can switch to RDM, or in some cases the tank can switch to DPS because of the sync being a joke.

Or they could let the party initiate a vote to make the dungeon harder; if they vote yes, there are buffs to the damage output and other mechanics, in exchange for greater rewards (higher tomestones).

If the vote wins ie. 3 players vote yes, they must be pretty confident in their ability to carry the sprout/returner through it. On the other hand, if there are 2 sprouts/returners there, maybe they both aren't confident enough for the difficulty setting and will vote against.