Subscription Management Tool (SMT) is not a patch management tool. It’s a package and update mirroring tool. The clients still need to actively fetch updates from this mirror.
SUSE Manager is a complete management solution for SLES and RHEL, including asset management, package management, patch management, (simple) configuration management, monitoring. All functions can be run from the SUSE Manager web ui. SUSE Manager is the best solution for pure Linux management.
ZENworks Linux Management supports Linux and Microsoft Windows clients and thus has a more ‘alien’ interface to admins with Linux background.