I have a theory about testing this.
1. Choose a pantheon to test with, preferably with a bunch of things you don't need.
2. Evo everything else in your box.
3. Un-Ult-Evo your test pantheon.
4. Run weekly dungeons and track your results
5. Sell the evo mats for 1 color without using any of the rest
6. Run weekly dungeons again
7. Repeat for various combinations of needed evo mats, including no evo mats needed.
My theory is that there really is a desire detector for things you *don't* have, which is why people get a million of Dark Mats when they need Light Mats. Thus if you want to increase the drops of say, Dub-topalits, you need to have a bunch of them in your box.
This is undermined by the fact that GungHo can control the ratios behind the scenes, including standard gambling stuff like hidden hot and cold days, servers, hours, mats, etc. There may even be a real AI running the show in the background, applying psychological heuristics to each player individually to increase purchasing. How many millions does this game make again?