To be threaten as unequal, first step is to be clustered into one group, or groups. This means that every person should take place within a sub-group before fighting for equality.
This is also related to human being. Let's imagine that we have an opportunity to give to all people equal opportunities under equal starting points. There will always be people who aim to achieve more, this is natural even for all living units. Hopefully, there will be, since we would never have seen any innovation or development in the world.
Apart from this situation, when we mention inequality, we have pre-learnt sub-groups. Even there might be other sub-groups (small or large), statistically or in order to have more credibility, one has to wait until these groups become clustered naturally or cluster through the global attention.
If we believe in equality, and fighting for it, should we really wait for this clustering? If we would achieve, shouldn't we really threat all sub-groups equal, and think about more inequality may exist in all tiny sub-groups even they are not yet sub-groups?