Ithink what he is saying is that you dont have an "actual" group of something unless the things are exactly the same, other wise you have two distinct things instead of 1 group.
I disagree, you have a group of humans. No humans are individual in the sense they they, their thoughts, and actions are independent from a group of others whether those others are "the same" and the thoughts and actions of the individual corespond with the group that is the "same" or whether the group is different and the thoughts and actions of the individual are the direct result of opposition to the different group.
Human instinct in newborns is to form bonds with others, to learn to do what othersdo and to develop into something that adds to the culture it was born in and reared by. Basicly we are born a component of our culture, our "individuality" is what makes us useful to the group, as in it wouldnt be of use for an organism to develop into something that has two of one organ, (in some cases but this is an illustration) so it develops into something with coresponding organs that function coopperatively togeather relative to an over all purpose; that is the one body, which in turn is developed to relate to other bodies in that groupor body of like creatures.
Back to the original statemnet and disagreement. You can have two TV's of two distinct designs and age, put them togeather and you have a pair of TV's, the essential function is the same and the defining structure of what it is so they are a pair, add another and its a group regaurdless of make and model.
The real question is why are such a group dependant primates going around ranting about individuality from within their collective?