Some of the trash mobs 150+ have dps check mechanics, 2 second donut one shot AOEs and start hitting really hard even on a tank.

Flood Dragons would be a pug nightmare, if you have a slow cleansing healer you are going to have problems. (It puts a frostbite that kills a dps in a couple ticks if it isn't removed immediately, the initial damage brings them down to half hp, and it's a puddle AOE and can hit more than one person at once.)

If you have a good interrupt/stunner it makes it so much easier to deal with the trash in there. Honestly the trash is harder than the actual bosses. You have to be very careful once you hit 180 as there are so many ways it can screw up and just end your run.

I haven't been in there since clearing so I don't know if they nerfed any of the trash since then. RDM would make it easier I suppose and there are sustaining pots now.