Example: comparing the suffering of Native Americans or European Jews. Each group had its own unique challenges and faced its own unique obstacles. Their persecution or repression evolved from vastly different trends and motivations in society. Short of the objective fact that being considered a piece of property and not a human being is one of the most dehumanizing and traumatic acts it is possible to impose on a person, it is better to look at, in my opinion, a broad struggle for equality within an impersonal legal framework supported by variously motivated establishment figures. Otherwise, you risk obscuring the suffering and struggles of one group because group X had it worse.
So, to conclude, certain acts may have been undeniably worse or more repressive, but to compare them to other groups is of dubious merit and risks starting a meaningless and historically irrelevant competition.