I'm sorry this made no sense to me. Don't think so is the answer if the question is what I think it is. Feel free to prove me wrong if I am though
Well ATA seem to have given up on drop rate ideas. As it currently stands HTE drops the most (wonder why) and I'm guessing drop rates will go from high to low following the tier of Eb. Chest drops seem to be a little more random. My observation alone won't be enough though ask around to find the best ebs or just take some time to check other clans eb histories.