How do you know when you have enough positive discrimination?

Do you just make sure that the representation of different groups is the same as in the population? This is a poor solution because it cannot be said that this would have been the distribution without negative discrimination.

Also, along what lines would you now pick your categories?

Would you ensure representation for latino lesbian women who speak spanish and like chocolate cake on tuesdays?

Which is to say that the category can get arbitrarily small.