'Server' attribute of pack cluster is 'server_master' ?

I have a Pack cluster as follows:

Master -> Hostmaster (server_master)

Slave 1 -> phobos.int.mig5.net

Slave 2 -> deimos.int.mig5.net

The pack 'server' is called 'cluster-web.mig5.net'.

The drush alias looks like this:

$aliases['server_clusterwebmig5net'] = array (
  'context_type' => 'server',
  'server' => '@server_master',
  'remote_host' => 'cluster-web.mig5.net',
  'aegir_root' => '/var/aegir',
  'script_user' => 'aegir',
  'ip_addresses' => 
  array (
    0 => '106.187.40.34',
  ),
  'backup_path' => '/var/aegir/backups',
  'config_path' => '/var/aegir/config/server_clusterwebmig5net',
  'include_path' => '/var/aegir/config/includes',
  'clients_path' => '/var/aegir/clients',
  'master_url' => 'http://aegir.mig5-forge.net/',
  'admin_email' => 'admin@cluster-web.mig5.net',
  'http_service_type' => 'pack',
  'slave_web_servers' => 
  array (
    0 => '@server_phobosintmig5net',
    1 => '@server_deimosintmig5net',
  ),
  'master_web_servers' => 
  array (
    0 => '@server_master',
  ),
);

My question is: is it normal that the 'server' attribute for a pack is '@server_master' ? Despite 'remote_host' being correct?

I noticed this because the drush alias for my site mig5.net, which is on the cluster, is also thus defined as 'server => '@server_master'' and I expected it would actually be '@server_clusterwebmig5net'.

Figure if *I'm* confused, then it probably needs to be explained in the docs :) or else it's a bug?