Perfectly fine. An Continuing on from your example, if John Moe Doe IV named his son John Curly Doe after his father, he would be right to be called John Curly Doe II, however John Curly Doe the elder wouldn't be referred to as J.C.Doe Sr.
"All religions, arts and sciences are branches of the same tree." --Albert Einstein
"Hatred paralyzes life; love releases it. Hatred confuses life; love harmonizes it. Hatred darkens life; love illuminates it." ~ Dr. Martin Luther King, Jr.