Multiple HA server on ONE network. - Wider Zigbee range

This is by the way more or less roughly explained in the ZHA integration introduction, adding devices, and troubleshooting sections (which among other things list limitations), see:

So it is highly recommend that you read through all of the ZHA integration documentation regardless:

But best is to do more research yourself yo learn more about Zigbee, so suggest start by checking out the cookbook guide links: