Hi Jim, I agree with you that those names are rare in the United States, Colin Powell is a first generation American and he pronounces it well.... differently.
It seems as though some names just become less popular, The Zekes an the Jakes.
James, John, Paul, David, seem to be popular everywhere. The only two Vaughn's I've ever met were a Newfoundlander and an Australian.
The Todds and Chads seen to be confined to North America. I think a lot of America's children get named for movie stars and characters in soaps.