I've suspected they're both Marshalls. Yasopp's and Banchina's surnames are unknown. Oda said Blackbeard would be from Somalia and Usopp from an unspecified part of Africa too. Definitely not a coincidence, especially as Somalia is part of Africa too.
Marshall can relate to cowboys/wild west/gunslingers or w/e too ofc, Sheriffs, Deputies, Marshalls etc and I had the headcanon either BB or Shanks would have a Sheriff with either Shanks or Blackbeard and their deputies with their top commanders or first mates only at least and so on. Maybe enforces or something for the rest? Lafitte was a sheriff too IIRC?
@Moewu @Rottkins @CoC: Color of Clowns thoughts?
I never considered Blackbeard being an evil Usopp from the future, that would be INSANE LMAO, I kinda love the idea at least! Usopp suddenly becomes one of the most intense, terrifying, cunning, deceptive, manipulative characetrs ever, especially in a dark/evil way ofc!
Far better twist than even Aizen by far! Or maybe thats just my Usopp and Blackbeard bias talking too lmao.
Seriously though it cant be possible given what we know but I do genuinely think they are actually related, one of Usopps parents could be a Marshall?
I believe Usopp is a Noland too, through one of his parents. Oda is setting up the clues, signs bigtime imo.