Hi Ray,
I have to agree with you completely. Two ribs are definitely overkill. I started tying and fishing Czech nymphs last year. After tying my first couple of dozen according to the pattern book, the rib under the shell disappeared completely. I can honestly say that not a single trout, brim or bass ever complained. I've never been a belt and suspender man when it comes to fishing flies. 8T
BTW, I wrap that single, outside rib down pretty hard so it definitely stays in place. I make sure the mono bites into both the shell and the body dubbing.