The first question, before I start, is the choice of coil voltage.

I have set the bar at 200 relays so I must estimage the required energy when all the coils are activated.

The lower the voltage, the lower the resistance, the higher the current...

I could undervolt the system a bit using 3V or 5V relays will require large busbars.

The question of fanout is important as well, because some things will switch 16, 32 or maybe 64 coils at once. That's a lot of current ! So I don't look at 2A relays like before ("why do I need so much ?")