Really depends on the context of the dungeon and how you do things. A lot of people are not going to enjoy farming something like that unless there are rewards for doing it the fastest and so on. In other games I've seen this kind of thing where you have to finish things and score points in a certain time with parts that you need to split up on. The first thing is figuring out where to place each party member and then learning to optimize what you do. If there were whole sections to go through soloing trash mobs then it would be boring but if sections had trash where they are designed for a certain party member and have class specific mobs and a puzzle to solve that could be interesting.,