/subsystem=jca/workmanager=default/short-running-threads=default
/subsystem=jca/workmanager=default/long-running-threads=default

Thread group with name default-threads is created for both of these addresses. It's because thread group name is created from last element of resource's address + string -threads.

ThreadPoolManagementUtils.java#L166

params.name = pathAddress.getLastElement().getValue();

ThreadFactoryResolver.java#L149

protected String getThreadGroupName(String threadPoolName) {
  return threadPoolName + "-threads";
}

Thread groups for different resources shouldn't have the same name. Also such a general name default-threads could be confusing when debugging.