Well there’s a lot I can list honestly, but off the top of my head, I would like to see Napoleon talk with Jeanne d’Arc.
Napoleon was one of the few political men who openly talked about how some of his biggest role models were powerful women; And one of those women was Jeanne d’Arc. She was a country side girl with no education or training who, within a year, became an remarkable leader and cannon artilleryman. Napoleon spent many years training to become the leader and cannon artilleryman he is known as today. There’s really no reason FGO Napoleon shouldn’t honestly be depicted as a huge Jeanne d’Arc fanboy.
It makes no sense to me that Napoleon, who 1) had paintings and statues of Jeanne d’Arc around his home, 2) is rumored to have named one of his cannons after Jeanne d’Arc, has dialog lines for Iskandar and multiple other Greek heroes before he even gets one line with Jeanne.
But yeah, that’s just one of the pairs I’d like to interact more. Thank you for the questions anon(s)!