What is unique or rare about the VM Zodiac signs?

[MarcoP]

Even if You are not allowed to view links. Register or Login to view. describes the illustrations in M II 180 as the 12 signs of the zodiac, the presence of Lyra, Cygnus, Draco and Puteus suggests that the cycle is about the constellations. But of course constellation and zodiac icons were largely interchangeable.
From You are not allowed to view links. Register or Login to view., I guess that the same is also true for Cancer in ONB You are not allowed to view links. Register or Login to view. (Prague, Bohemia, 1375?-1400). This one could be interesting both for the time frame and for the presence of the correct number of legs.
The other two examples are rather different from the Voynich Cancer, but I think they could belong to the legs-on-tail type? These two clearly represent the zodiac sign, since they illustrate calendars.

My opinion is that we can say that the feature is rare, not unique.