Lol - the small and xs fasten the other way because it is meant to be easier to change, the larger sizes reverse because it is harder for baby to undo.
I def agree that wool is fabulous for night. There are various wool instructions on bumfluff, or I can send you an essay email thingy again on the joys of wool
You are best off with knitted wool for night imo, they have that bit more give (so not like the sugar peas or swaddlebees). Woollywraps give a lovely fit and I find them really reliable - I had to shut that section because they had family things going on, but I think they may be reopened, so will hopefully have them back on sale in the next couple of days.
For a handknitted more personal wool you won't go wrong with seahorse slacks or pixie knits.
The hollow oak do gorgeous felted (I think it is felted) wool