my grandmothers 3rd husband (yes 3rd

and shes still going through them!) had the name john harry at birth. unfortuanltly he had a brother john james and his father was john also. so john harry was known as harry, john james was james and john sr was john.
after the death of his brother john harry became john 2 and john sr was john 1! then when john harrys father john 1 died john harry became harry again as he didnt want to use his desceased fathers name!!
so i would say it could be quite common!