look, i'm also very tired with some brands riding on the cdiem aesthetic and concept. there have been some new names that bring nothing new to the table. in fact guidi is also a rip off of cdiem in some ways (hint: they were originally a tannery). to some folks it matters, to others it doesn't. Personally, I really dislike that. But jun is quite simply not a rip off, nor is wjk a "new" establishment. so you can set your mind at ease over that.
in terms of quality, i think most people would say wjk far outstrips ccp. ccp stuff is uncomfortable and a bitch to wear, and some stiching is not all that durable when i inspected them in person.