Load Balancing is automatic between multiple collectors within one failover group. The issue is when you do not want collectors to failover or load balance between the two.
Load Balancing is a feature within nWorks and it is set to work automatically by design.
Load Balancing guarantees non-stop monitoring of infrastructure and therefore it is not possible to switch this feature off. As a work-around you may create separate failover groups for each VMware farm and assign only one collector for each group.