Hello Issac,
On this link that you have there is a quick explanation about in what situation you can have multiple Robots:
"Some situations are best addressed by installing multiple robots on a single host. For load balancing, you can install an additional robot on a single host to run a specific probe: for example, the discovery_server probe. For performance reasons, you can install the Unified Management Portal (UMP) on a child robot of the primary hub when monitoring small networks. For load reasons, you can use multiple robots on a server to run more than one instance of a single probe: for example, if your SNMP devices are only reachable from a specific server and you need to run more than one snmpcollector probe, you can install multiple robots on the same server for the same probe."
Kind Regards,
Alex Yasuda
Sr. Support Engineer