There should be a place in the documentation where some architecture or infrastructure decisions that may be abnormal are explained, like:
How SIMP assumes an admin would manage packages
How SIMP assumes people want to provision their systems (kickstart)
How SIMP assumes an admin would want to distribute large files (rsync)
The security_conop guide is thorough and explains a lot of these types of assumptions, but we should further explain things that would confuse a new admin, even if they have set up their own infrastructure before.