GOOD QUESTION. i don't know if he might have voiced an objection if only because then he'd have to explain WHY and that just opens up a whole can of beans, so should we go for the second option because that sounds like tons of fun. a lot of people underestimate vash because he's goofy and makes dumb decisions but he's actually a lil smartypants, so having someone in his corner on the dauntless would actually be awesome and make a lot of sense? so it's def possible he at least gave her some info - enough that she takes the job and put him in a position where he can hit her up for information and or to get her involved in some craziness