I'm not saying it can't be done properly, as it can but as of now that area is by far the easiest to do it from. The conventional method of sticking to the back of the room behind the 2 containers still works.
As for you getting less loot, you're more likely to notice when you don't get any and someone else does as it feels like some kind of injustice. I doubt you can get the best loot available at lv21 either, expect to still get lv18 blues the majority of the time. If you're looking for guaranteed loot, maybe try the strike playlists instead as their loot as been buffed recently
The way things scale with more people in this game I'm not surprised one lv28 found it easier than 3 lv27s. With 3 people the HP of enemies has doubled, their damage is scaled up slightly and you also need to take the level penalty into account.