I would say that what ever numbers you use, you always face the prospect of the claim of over or under representation.   Who gets to decide what the right numbers are?  I also think there is always going to be charges of institutional racism or sexism until it is clear that there is no special treatment.   Also, talent and need do not always break according to whatever numbers you use.    Suppose, one group of the population commits 70% of the crime but only makes up 50% of the population.  Do you arrest people based on the percentage of the population?