It is a real pain to get traitstones, and it starts with finding the right kingdom to explore. We can easily eliminate that problem by adding the graphics for the traitstone right onto the kingdoms on the map.
I suggest removing the little gold curly braces on either side of the Kingdom name, and placing one color stone on each side. That way you can simply see the colors you will be getting for each Kingdom right on the map.
Many of us use a 3rd party tool.
Gems of War Database (Only works for PC/Mobile)
its free and will help you find and know what you need. On the right side, where the traitstones are, you can hover over and get the names of each kingdom that matches it.
I was sad when I found that tool a few months ago - since I play on the Xbox. It really is a great tool.
I think part of the problem with this idea is how cluttered the Mobile experience already is on the screen.
I do think something like opening up your “collection” under the hero and clicking on an Arcane Stone should highlight what cities can drop it, or something else, even just city names from where it drops.
I just downloaded the mobile app, and played the tutorial so I could see the map. It would not change the clutter at all. Just replace the gold swirls on the edges of the kingdom name with colored circles of the same size. It would give you more information without taking up any more space.
You can view the kingdoms and which traitstone they drop on this page:
Not saying you’re idea isn’t a good one (it is), just this can be useful in the mean time.