Some more info case somebody is interested.
I threw out
server/default/deployers/jbossws.deployer/**
server/default/deployers/jbossws-jaxrpc.deployer/**
server/default/deployers/resteasy.deployer/jaxb-impl-2.2.jar
lib/endorsed/jbossws-native-factories.jar
lib/endorsed/jboss-jaxb-api_2.2_spec.jar
lib/endorsed/jboss-jaxws-api_2.2_spec.jar
lib/endorsed/jbossws-cxf-factories.jar
common/deploy/jbossws-console.war/**
So I could put my own jaxws runtime in it.
But that meant server/default/deployers/jbossws.deployer/META-INF/stack-agnostic-jboss-beans.xml was also removed, which defines the 2 WebService resource providers.
So my fix was to patch this deployer for my sake and only leave those 2 bean definitions, which seems to work ok.