I wish I could agree, but, I feel this sound more like a cop out. A XenServer is a hypervisor that's a minimal version of RHEL. If you were to perform a CD install, you're going to end up with the same installation on all of your servers.
Even if I were to keep what you've mentioned in consideration, I'm going to point out a few items, that is key in the success of the deployment, which aren't even mentioned in your document.
I had to install a bunch of RPM packages just to be able to install RRDTOOL or PHP 5.2.12. Perhaps you can update the docs to actually discuss the needed packages. Luckily, I'm seasoned enough to walk through this and install the required packages, but, I can't say the same about everyone else.
That said, a good application development process will always require a good set of documentation.