Photos: Consolidate duplicate name suggestions for faces

When I enter a name for a person's face, replacing "unnamed," I see a suggested list of names that start with the same letters I have typed. That's great, except let's say I'm entering the name "Joe Smith", and my drop-down suggestions include 3 or 4 pictures of the name "Joe" and maybe 1 or 2 with the name "Joe Smith." Each suggestion has a different thumbnail, but they are all of the actual person "Joe Smith."

How can I remove duplicates and ensure that all my Joe Smith pictures have the same name assigned to his face?

Thanks so much for any help!

William