Don't get me wrong, Isabelle, Grace, George etc are all nice names, but it would totally take the shine of it for me if there were likely to be 2/3 kids with the same name in their group.
To be fair, I grew up with a super odd name which I have never lived, but it does surprise me that people choose names knowing there will be people in the same class with the same name. Maybe because I've never had that experience...but still seems odd, especially when there are lots of names which aren't unusual but which aren't everywhere