Acceptable Champion Diversity Environments

One of Riot's stated goals for LoL is to have a lot of champion diversity: the more the merrier (but doesn't have to be 100%). What if there was a world where every champion is viable but it's because every champion had one and only one other champion that you can play against it.

Would that be better than only having 5 champions per position? Remember, not saying is that the ideal future but is that just relatively better than limited viability.