This actually highlights, what we're coming to realize as a serious issue with the current SSG content.
I should be able to *easily* start from a base, replace the parts that I need to, trace back to the original information, and set my own parameters.
Setting my own parameters is reasonably easy, but the rest isn't.
My answer to your question:
1) There should be a base CNSS 1253 policy that is the common XCCDF ground
2) Each branch should have their own derived CNSS 1253 policies that override the requisite XCCDF and OVAL content as necessary
3) Nothing should be repeated that is not overridden
4) Overrides should be understood in the derived content
5) This should be easy...it's not (actually, it appears to be impossible without tying yourself in knots)
Since we implement controls in a cross-system manner, per application, SIMP has needed to derive the various controls and change OVAL content to match the way we do things. This should be *easy*. It is absolutely not easy and I don't think we'll see larger ground level adoption until it is.
Thanks,
Trevor