The thing to understand first is that the Livestream Repeater (origin/edge) system is one thing, and load balancing is another. Completely separate. They are used together obviously, but are separate systems.
A LB Listener and one or more LB Senders is the load balancing system. An Origin and one or more Edge servers is the liverepeater system.
Typically, an Origin server is also used as the LB Listener. But that is not necessary for this to work, it’s just typical and convenient.
On the other hand, a LB Sender is always also an Edge server, it doesn’t work if these roles are not paired.
An Origin server is what you publish a stream to. Edge servers restream from the Origin. So this is how streams are distributed.
A LB Listener redirects connections to the LB Senders (which are always also Edge servers).
So the thing to do is set up an Origin server, then setup one Edge server. Test that by publishing a stream to the origin server playing it from the edge. Then setup the Load Balancing system: A Load Balancer Listener, and Load Balancer Senders on the Edge. Then add Edge Servers and Load Balancer Listeners as necessary.
Clients get “least loaded server” from the LB, then they initiate streaming with that edge. The LB is not involved beyond that, no involvement with streaming at all.
I hope this helps.