I have noticed that also. The bottom of the pecking order here had blood on her back from pecking. We put her in the hospital for a week or so. The other birds would visit her, but when it was time to be released the bottom birds were relentless on her. She is a smaller timid white EE, and spend most her day running from the others. She is even afraid to enter the coop at night. I have to wait till she roosts somewhere and carry her into the coop, and place her on a high deserted roost area.
My birds have 100's of acres to use, and still this one is picked on. The sad part is I like her and I think I will keep her for my flock. When the rest are departing she and 12 others will get to stay.
It was recommended to me to remove the one who does the most bullying for up to 2 weeks thus changing the flock dynamics and the bullying should be drastically reduced but if it's not, then consider culling the bully.