if he ever needs to hire a thief, vash could do it! his ship the sparrowhawk primarily deals with a lot of uhhh not legal work too and lots of thievery and smuggling. definitely yes to friendly neighbours, and definitely running across one another on antillia. they could've either crossed paths in the criminal world and maybe again when it came to races, if he knows ~bionics through that? vash raced sometimes too without sponsorship, since he doesn't like being told what to do lmao so he's mostly infamous for showing up, winning races in shitty ships and disappearing again