You want to create system containers and have them exposed directly to your LAN. That is, these containers will get an IP address from your LAN’s router, or, if you insist, setup yourself manually static IP addresses in each of them. If you have access to your LAN’s router, you can configure it to give the same IP address for each of your system container. If instead, you want to set static IP address in each container, then this is up to you to get correct as LXD is not involved at all.
You can expose system containers to your LAN, using either a bridge or macvlan, when you connect your computer to the LAN with an Ethernet cable and NOT through WiFi. Because with a WiFi connection, only a single MAC address is accepted by your WiFi router coming from your host (due to WPA, etc).
If you have a router that is too smart and secure, it might enforce port security, which means that even with a cable connection, it only accepts a single MAC address from your host (so your containers are not visible on the LAN).
macvlan is easier to setup, it has a feature that the host cannot access any of the
macvlan containers. If that is a problem, use a