It seems to me that v is an "older" version and that the W is becoming more popular. Also I see the J/Y in much the same way.
Is there a reason that J goes with V. What about JHWH? I'm not much of a linguist so this is based off what I have read and seen.
Side note: have you heard the idea of these being the sound of breathing and not meant to have clear pronunciations. Any thoughts on that.