Being pre 90s (barely), I felt the need to reply.
I slept under a poncho during service many nights. In the summer and winter, during the good and worst weather. Never got wet or blown away.
The poncho i used was the dutch issued model, cut the storage bag of, and knotted 4 shockcord loops on the corners. Setup was alway simple; take 1 piece of cord, or 2 pieces of shockcord (the thick stuff found on bikes), find two trees and take 2 corners to attach to said trees. this make a lean to. I preffered to keep it very low, low profile for weather and foe's.
When available we used the snap buttons/fasteners to double up a lean to, or create a very long uoside down V for 5 ore more.
Pegs were in my backpack, but if i had some spare time i replaced them for wooden ones so I wouldn't have to look for them in the dark/rain.
a bit more complex example:
click here for big picture