That sounds right. We built this ability so that people could distribute LEM appliances and monitor from a single place - usually it's a single environment with multiple departments or regions (like a bank holding company with multiple banks, or a geographically disperse company with several LEM deployments per region but a parent datacenter that also needs visibility).
You should also be able to import/export those groups across appliances for when you need them ON the appliance (for things like scheduled searches or rules where they run from the appliance, not the console). Create on appliance 1, export, import into appliance 2, etc.
I'd say you're pulling LEM in exactly the direction it's intended, we just haven't made it as far as you have yet.