I like sleeping under tarps. But if the bugs are bad I add a mesh inner tent. There's no question that a full tent is warmer. And if there's a serious deluge a good bathtub bottom can save your bacon. I guess I just like to look out at the night.

Regarding the OP: If I understand correctly, the "shelter group" that's being referred to includes a dome tent, sleeping bags and pads, and tarps.