My brother and I are in the same alliance. I am usually the top titan damage dealer. He is usually in the top 6. My loot is usually a tier higher with an A grade while he has a B grade a tier lower. He recieves on average 3 times more 4* ascension materials than I do.
Also if I intentionally get 5th or 6th place in damage I also tend to get a lot more 4* ascension materials.
Unfortunately my high damage is pretty essential to my alliance successfully killing titans, so I am knowingly getting screwed on titan loot by getting A grades in high tiers.