Splunk Add-on for Kafka: Does managing inputs manually from each Heavy Forwarder create duplicates?

I have two Heavy Forwarders configured with the Splunk Add-on for Kafka. Now if I manually create input topic messages from each forwarder, won't that become a duplicate? I wanna maintain a balanced topic load between these two forwarders? How do I achieve this? Sorry if my doubts seem naive, cos I'm just trying a POC on Kafka-Splunk connect.