Remember that "DF groups" can often be "5-7 man premade groups that went through DF to fill the slots".

Yesterday we wanted to do T5 for a friend who returned from a break, after waiting for a while in PF we decided to go through DF to fetch a healer and a dps, while they did make the clear harder we ended up asking them to suicide before divebombs and got them (and my friend) their clear.