How to share the display of a laptop with 8 more laptops without flicker?

I want to have 9 laptops' screens shared. so that one of them is master and the other ones see what is done in it.

I first thought about using HDMI cable. but it doesn't work for more than one additional laptop.

Then I thought about teaching softwares such as NetSupport School which it is possible to use LAN cables to coect many computers to each other. but I have seen the display of a client computer that was coected to such a system. It flickered.

Isn't it possible to have such network with HDMI cables (for EIGHT client displays)?

Or is there any alteative?

By master I mean the laptop whoose actions are seen. And by client or slave I mean those which see the activities of master laptop.