I don't think this is a swell dungeon for the DF system. It's very unforgiving to new folk, and the allotted time limit just isn't enough. Even with a fair trip around with learning the encounters, the allotted time limit is pushing it.
I have no doubt with all four members who know what's going on, they could wipe the floor with the place. But that's just a fact of gaining experience and learning. Having gone through that I have the firm belief that this dungeon is just too unforgiving with it's time limit for people who have a different group on every run they attempt through DF.