There is currently no API support for setting the installed packages on a host. The only way is through the /rhsm API which is not meant for usage by scripts/hammer.
Created from redmine issue http://projects.theforeman.org/issues/15079
Per 6.3 planning, moving out non acked bugs to the backlog
Upstream bug component is Hosts - Content
Upstream bug component is Hosts
Thank you for your interest in Satellite 6. We have evaluated this request, and we do not expect this to be implemented in product in the forseeable future. We are therefore closing this out as WONTFIX. If you have any concerns about this, please feel free to contact Rich Jerrido or Bryan Kearney. Thank you.