My family is full of multiples including myself so I really don't think much about the similar names that have been given.
My brother and I have first names that start with the same letter -
John and
Justin (even though we go by
Johnny &
Sammy - his middle name). Our older brother and his wife have triplets with very different names -
Joshua Alan,
Anna Jane, and
Niklas Avery and their little sister
Nicole Dakota really has a closer name to
Niklas than the triplets have. I have twin boys that have similar names but different enough to be ok -
Markus Paul and Mattias
Petr and we call them
Mark and
Matt. I think names that are similar to the extreme such as
Nick and
Nikki aren't good and only confusing but names like
Mark and
Matt are good names.