My husband is the IV (4th) and he wants to name baby V (5th)

I really don’t know what to do. My husband is a 4th generation same name. First, middle and last. I can’t say that it’s the best family tree with a close knit family and lots of tradition. It’s more a disconnected family we still see but wouldn’t consider ourselves very close with. His mom made a comment that we “have” to name it the 5th it’s a tradition and we can’t stop it now. Meanwhile she’s divorced from that family with very little connection.. I haven’t had a super serious conversation with him he knows I’m not thrilled with that idea though. I am very torn.. I do NOT want to be controlling and cut him off from that traditional name if it’s immensely important to him BUT I reallllllly do not want my son and my husband to have the same name. I never wanted that... I don’t know what to do. Any advice or anyone who had been in a similar situation?!