in my earlier version of this Idea https://forums.factorio.com/viewtopic.php?t=129683 I used 2 signal for every resource, and also needed to create a blueprint for every new station type that I made, like iron plates, steel plates etc.
Now only one signal is used per resource and its icon is also ...

So, I started my first marathon playthrough, and chose to make cityblocks really early (as soon as I got them at green science if im frank), and there I met factorio limits - trains when going to stations with same name - go to closest one, so when I dont have enough input/trains it leads to them ...