[Opinions] Re: Naming dilemma (Hypothetical!)
No, I don not think this would be a "bad idea". It would only be a bad idea if the two people were growing up in exactly the same household.
It was very common in previous centuries for there to be two or more first cousins with the same given name, and people dealt with it fine. When the two people are at the same family gathering, they can usually be differentiated by adding the middle name when one is talking about them. My niece is name Ashleigh and her brother married a woman named Ashley. When we refer to them in the family when it might not be obvious which one we are talking about we say "Ashleigh Marie" or "Ashley Suzanne."