Its actually a bit more complicated than that, because the machine which makes the color separations cant output them large enough for a full sheet, so the color separations are done in quadrants
Necron Dynasties is actually the first such precon to be released since Commander 2014s monocolored planeswalkers
Urza, Chief Artificer This is the only instance of affinity for artifact creatures (thats WotC making the mechanic safer)
For example, if 3 is not stored on Goblin Girder Gang and you roll two 3s, the ability will trigger twice
It's going to be loved in shells that care about enters-the-battlefield or reanimation
They have a lot of storefronts, and some are even clustered in a small area, so depending on your location, you may have multiple you can go to