That was my first thought - they look like they are being cooked. Chances are the spot you planted them in is much sunnier than the nursery was. Moving them immediately to that stucco wall was a little too hot much too fast - especially last week.
Watering 3 times a week until they are established is probably okay, especially if the temps in Las Vegas continue to be hot. If new foliage is coming out healthy, you are okay. They might lose a lot of those old leaves but new growth will assure you that things are good. Did you dig a hole twice the size of the plants and mix in some compost to hold some moisture? Or just the organic miracle gro? If not and they are planted in the native soil, you may have to keep up the 3 waterings a week.
Were they root bound in the nursery pots? If so, it will take awhile to break out of those root balls - that may be why they aren't getting enough water also. Buying big plants is always rewarding as it gives instant results but, in the long run, not the best choice. It takes bigger plants longer to establish.
They could use some fertilizer - something with some iron in it.
Daisy
edited: Hmmm... I assumed that one was a bush type. They are going to get awfully big for that small space.
