LOL, I admit I didn't expect them to share the love-is-blind trait, so I'm glad I mentioned it! Between that and some of the other stuff you mentioned, it sounds like we've got a bit of common ground here, along with some key differences.

If we go with them noticing the neat freak trait, maybe Prussia could see Barnaby's partner Kotetsu throw some trash on the ground, and then Barnaby gets on Kotetsu's case about it?

And as far as I know, Barnaby only speaks English.