Having just had an argument about this here is a slightly different slant. Suppose one box has nine identical red icecreams and one blue one and another box has nine identical blue icecreams and one red one. We could say the first box is more red than the second box, meaning it has more red elements, not that the individual elements are more red. So a team might have more individuals who are unique than another team and for convenience we could say it is 'more unique' rather than laboriously stating that it has more members who are unique. I don't see a problem with this although my friend disagrees strongly.