Matt Newsome has a nice section on his web site on box pleat kilts at

http://kilts.albanach.org/

The reason that you don't see 8 yards of tartan in a kilt like this is, as you'll see from Matt's website, because they are modeled after a very old style of traditional stitched-pleat kilt. A traditional box pleated kilt has a small number of wide pleats (7-9 or so, depending on the tartan). 8 yards of tartan in a knife-pleated kilt is actually a rather modern invention (more or less since end of the 1800s).

Someone else should talk about military box pleat kilts. I've heard several different stories about how they originally developed. Maybe Steve Ashton could describe the origin that he told me at Kilt Kamp a couple years ago.