What is unique or rare about the VM Zodiac signs?

[MarcoP]

There's also the earlier (still later than the VMS) example from post #11:

Two sets of two crayfish each appear in You are not allowed to view links. Register or Login to view. (Western  France, 1455-60).

I think it's possible that the Lyon ms derives from NAL 3191, but who knows? There also are considerable differences, e.g. in NAL 3191 most of the signs appear multiple times, like two couples of crayfish (red and black), sitting and standing bull etc.
(top NAL 3191, bottom Lyon):
   

About double cancer, it might be worth remembering this ms from post #46

As far as I know, double crabs appear in a single manuscript: You are not allowed to view links. Register or Login to view. (England, ca. 1325-1330, discussed by Olga Koseleff Gordon).

Gordon's paper is You are not allowed to view links. Register or Login to view..

Here cancer is represented as two crabs seen from above, inside a circular frame. Personally I doubt that NAL 3191 derives from the much earlier English ms: I think it's more likely that double-cancer was independently created at different times and places. But, again, who knows?