the way i see it, when battlefield is generated, it doesn't mean that the quests are distributed evenly amongst the dungeons. instead, one might find that quests can be clumped together in one dungeon.
this happened to me in the 1st Act where 2nd, 3rd & 4th quests are clumped in the 3rd dungeon. in the 2nd Act, about the same thing happened where i have 1st, 2nd & 3rd quests are in the 3rd or 5th dungeon.