Actually it’s a little more complicated than that.
The full SandBlast Agent (now Harmony Endpoint) does share a couple components with the Endpoint Security VPN client (namely desktop firewall, compliance, and self-protection mechanisms, and of course Remote Access).
Even if you install as Check Point Mobile or SecuRemote, I believe there is a small amount of overlap.
You wouldn’t use the SBA Nano Agent on something with the full Harmony Endpoint suite installed but you can use it on other systems.