No, tent stakes are not very useful. You will, however, need to anchor things down ‘freestanding’ or not, as this is spring time and winds are the norm. Especially with a squally forecast.
½” is significant precip, especially as it is often delivered swiftly. Dry sandy washes can turn to torrents in minutes.
Really the type of shelter is a personal preference, as long as it is stable in strong gusts and goes to the ground all around. Desert wind /rain events comes from all directions forcefully. A carefully arranged tarp based on current conditions can easily become a wind tunnel full of driving rain.
Bring plenty of line to tie out to bushes and boulders, or to bury sand filled stuff sacks as anchors.
The Maze especially offer an abundance of protected rock shelters, either as a stand alone solution or to help a tent face the elements.