I can see why SEGA chooses not to post drop rates, loot tables, etc., and only has the ability to see if a quest dropped a thing at all. Imagine how much more people would be complaining if we could see the numbers, then they would try to math it out and still claim their 400% is broken.
It's tough beans yall, the only people who come onto forums or YouTube comments to complain are the small minority having a problem with it, not getting the rares they think they deserve because they paid real money. You have to assume the majority of people who buy these, have zero complaints or problems with it. For such a 'huge' thing this supposedly is, I've not seen anything on it besides this forum thread and a some comments on that one YouTube video posted earlier in said thread.
I run with the same people all the time who just so happen to always have better RNG than me. Getting easily 11 star armor units from bosses and lightning dog, but I barely eek out a 13 star Talis once every 2 weeks lol. Sure it's frustrating, but it's all just random guys and gals.