As explained to Bruno:
Basically we have a lot of configuration files which are shipped:
domain.xml (which includes the same stuff as in the standalone*.xml ones)
In addition there are a number of other example configurations that are shipped in docs/examples.
The problem is that at the moment these all duplicate stuff (with some minor changes in certain cases, e.g some extra settings in ejb in the ha setup). At the moment, when a subsystem has its configuration changed, you need to go through all the files mentioned and make those changes. This is not so bad for the 'core' files since most of those get tested but it is a frequent problem that AS won't start for the docs/examples configs because people forget to keep those up to date.
What I am doing is extracting out all the subsystems into individual files with different sets of 'tweaks' for the different configs and assembling the result files for that.