How to set up isc-dhcp-server to set all router NICs to the same ip and give out static and dynamic ips based on the interface?

I am assembling a set of server/router devices to be used as a provider of some offline services for the local network.I don’t need WAN, each server is isolated and for each server I have a set of ethernet NICs and 2 WNICs. I will be running hostapd to create 2.4 and 5Ghz wireless APs.

Each client should find router/server at the same IP (192.168.0.1) and
I want to dynamically assign ip addresses to the wireless clients, but eth0 and eth1 clients must always get the same static ips.

So far all tutorials for routers split each nic into its own subnet, this would solve how ip addresses are assigned on different interfaces, but then the server ip is different for clients on different interfaces. The second way is to create a bridge, but how would I give out constant static IPs to the ethX devices? is there a way to determine when the clients connect?