Instead of using <subsystems> and trying to limit content, I'm thinking more we have very specific elements that exactly describe what we support
<remote-management>
<!-- HTTP-based management capabilities -->
<http>
<connectors>
<http-connector interface="external" port="8888"/>
<https-connector interface="external" port="8889"/>
<ajp-connector interface="external" ports="8887"/>
</connectors>
<!-- Install a REST interface -->
<rest/>
<!-- Deploy the admin console web app -->
<admin-console/>
</http>
<!-- Remote java interface based on remoting -->
<remote>...</remote>
</remote-management>
When the SM starts the DC Server, it could translate that into the normal subsystem configurations that go into a Standalone, filling in the missing pieces with defaults.