Exterior wall joints

Hey all. Quick general question if I may; when building a timber frame construction with 2 layers of ply on the external face, I understand I should stagger the joints but can each layer be vertically joined if staggered or is it best to have 1 horizontal and 1 vertical? does it really matter? I'm building the reccommended 'sticky' double wall construction to (hopefully) give a STC of 63. I guess the same question applies to the 2 layers of plasterboard internally as well? Thanks.

I wish I could find the thread where I read about that, to give you a link, but I'm coming up empty! Anyway, from what I recall (I'm not an expert: just reporting what I read) for sheetrock (plasterboard) you really do need to go for 1 vertical, 1 horizontal, in order to minimize resonance and maximize isolation in your wall. I don't recall the detailed technical reasons, but that's the way that was recommended. Something to do with sheetrock panels having different flexibility across the long and short dimensions, I think. Hope that helps! Stuart